6 resultados para Sonae MC

em Helda - Digital Repository of University of Helsinki


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Tutkimuksen punaisena lankana kulkee kysymys siitä, millainen on bikerkulttuurin eetos? Miten se on syntynyt, miten sitä ylläpidetään ja miten Misfit MC:n jäsenet sitä tulkitsevat ja toteuttavat omassa elämässään? Tarkastelen eetosta kahdenlaisen aineiston valossa. i) Kenttätyöllä (vuosina 1995-1998 ja 2000-2001) kerätyn aineiston valossa tarkastelen yhtä pääkaupunkiseudulla toimivaa HD-moottoripyöräkerhoa, vuonna 1989 toimintansa aloittanutta Misfit MC:tä. Jäsenet kutsuvat kerhoaan useimmiten talliksi, joskus pajaksi, kerhoksi tai klubiksi. Puhuessaan tallista, miehet voivat viitata kerhorakennukseen ("tuut sä tallille?") mutta myös ryhmään ("meidän talli") ja sen olemassaoloon ajallisesti ja paikallisesti. Aloittaessani kenttätyön vuonna 1995 Misfit MC:n kuului kymmenen 25-30-vuotiasta miestä. ii) Kenttätyöllä kerätyn aineiston lisäksi käytän materiaalia, joka koostuu Harley-Davidson-moottoripyörän ympärille rakentuneen bikerkulttuurin historiasta ja kulttuurituotteista, kuten kertomuksista, elokuvista, musiikista, kuvataiteesta ja moottoripyörälehdistä. Aineiston avulla valotan bikerkulttuurin eetoksen syntyä, alkuvaiheita, leviämistä ja keskeisiä elementtejä. Lähdeaineiston monimuotoisuus ja runsaus palautuu kenttätyöhöni jolloin vakuutuin siitä, että tutkimusmatka bikerkulttuurin historiaan, perinteisiin ja median välittämiin (mieli)kuviin on välttämätöntä, sillä menneisyys ja Harrikkaan ajan kuluessa varastoituneet merkitykset vaikuttavat ja ovat vahvasti läsnä Misfit MC:n toiminnassa ja talliin kuuluvien miesten elämäntyylissä. Tutkimus etenee seuraavanlaisesti. Luku I on Johdanto. Luvussa II Etnografia käsittelen etnografisen tiedon luonnetta niin tutkimusasenteena kuin kenttätyön valossa. Pohdin kenttätyötä ja sen suhdetta etnografian kirjoittamiseen eli miten kenttätyöllä kerätty aineisto muuntuu etnografiseksi monografiaksi. Käsittelen myös kenttätyöni reunaehtoja, kuten tyttöystävyyden ja sukupuolen merkitystä, ja tarkastelen tutussa kulttuurissa tehdyn kenttätyön ominaispiirteitä. Reunaehtojen kuvailu toimii myös johdatuksena bikerkulttuuriin sellaisena kuin se ilmenee Misfit MC:n tallielämässä ja käytänteissä. Lopuksi pohdin "tiheän kuvauksen" mahdollisuuksia ja vaateita aineistoni puitteissa. Luvussa III Bikerkulttuurin eetosta kartoittamassa, kuvailen Harley-Davidson-moottoripyörän ympärille rakentuneen elämäntavan syntyä, levittäytymistä ja keskeisiä elementtejä. Tarkastelen media- ja populaarikulttuurisia tekstejä (elokuvien kertomat tarinat, musiikkikappaleiden sanoitukset ja HD- ja bikerlehtien artikkelit) ja kuvia (elokuvien audiovisuaaliset aspektit, kuvataide ja HD- ja bikerlehtien kuvitus), jotka ovat vaikuttaneet bikerkulttuurin eetokseen. Luvun keskeisiä - aineistosta nousevia ja miessukupuoleen vahvasti sidoksissa olevia - käsitteitä ovat biker, outlaw ja chopper, jotka ovat bikerkulttuurissa säilyneet alkuperäisessä muodossa maantieteellisestä tai kielialueesta riippumatta. Luvussa IV Misfit MC ja bikerkulttuurin eetos temaattinen painopiste siirtyy Suomeen ja Misfit MC:hen. Aluksi käyn läpi suomalaisen bikerkulttuurin muotoutumista ja ominaispiirteitä. Alkukappaleiden jälkeen keskityn Misfit MC:n jäsenten elämäntyylin sävyihin ja heidän käsityksiinsä bikerkulttuurin eetoksesta. Analyysin kiintopisteitä ovat Misfit MC:n jäsenten näkemys bikeriydestä ja tallitoiminnasta, miesten elämäntyylin moraaliset ja esteettiset sävyt, tallirakennus miesyhteisöllisyyttä ja bikerkulttuurin eetosta luovana ja ylläpitävänä sosiaalisena tilana ja Misfit MC miesten yhteisönä. Luvussa V Eetoksen ytimessä: mies ja Harley-Davidson keskityn bikerkulttuurin ytimeen: miehen ja Harley-Davidson-moottoripyörän väliseen suhteeseen. Luvun alussa esittelen ruotsalaisen yhteiskuntatieteilijä Lars Lagergrenin moottoripyörään soveltamaa työkalu - leikkikalu - toteemi - välittäjä -typologiaa ja tarkastelen moottoripyörän olemusta sukupuolittavana ja sukupuolittuvana artefaktina. Johdanto-osion jälkeen siirryn kuvailemaan Misfit MC:n jäsenten suhdetta Harley-Davidson-moottoripyörään. Lähestyn miesten ja moottoripyörien suhdetta kahden toiminnan - moottoripyörän kunnostamisen ja rakentamisen sekä moottoripyörällä ajamisen - kautta. Avainsanat: aineellinen kulttuuri, arvot, biker, bikerkulttuuri, chopper, eetos, elämäntapa, etnografia, Harley-Davidson-moottoripyörä, Harley-Davidson-moottoripyöräkerho, kenttätyö, maskuliinisuus, mieskulttuuri, mieskuva, moottoripyöräily, osakulttuurit, outlaw, populaarikulttuuri, sukupuoliroolit, yhteisöt

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Polyamines are organic polycations that participate in various physiological functions, including cell proliferation, differentiation and apoptosis. Cellular polyamines originate from endogenous biosynthesis and exogenous sources. Their subcellular pool is under strict control, achieved by regulating their uptake and metabolism. Polyamine-induced proteins called antizymes (AZ) act as key regulators of intracellular polyamine concentration. They regulate both the transport of polyamines and the activity and degradation of ornithine decarboxylase (ODC), the rate-limiting enzyme in polyamine biosynthesis. AZs themselves are negatively regulated by antizyme inhibitor (AZIN). AZIN functions as a positive regulator of cellular polyamine homeostasis, which by binding to AZs reactivates ODC and induces the uptake of polyamines. In various pathological conditions, including cancer, polyamine levels are misregulated. Polyamine homeostasis has therefore become an attractive target for therapeutic interventions and it is thus crucial to characterize the molecular basis underlying the homeostatic regulation. A novel human AZIN-resembling protein was previously identified in our group. The purpose of this study was to elucidate the function and distribution of this protein, termed as an antizyme inhibitor 2 (AZIN2). According to my results, AZIN2 functions as a novel regulator of polyamine homeostasis. It shows no enzymatic activity, but instead it binds AZs and negates their activity, which subsequently leads to reactivation of ODC and inhibition of its degradation. Expression of AZIN2 is restricted to terminally differentiated cells, such as mast cells (MC) and neurosecretory cells. In these actively secreting cell types, AZIN2 localizes to subcellular vesicles or granules where its function is important for the vesicle-mediated secretion. In MCs, AZIN2 localizes to the serotonin-containing subset of MC granules, and its expression is coupled to MC activation. The functional role of polyamines as potential mediators of MC activity was also investigated, and it was observed that the secretion of serotonin is selectively dependent on activation of ODC. In neurosecretory cells, AZIN2-positive vesicles localize mainly to the trans-Golgi network (TGN). Depletion of AZIN2 or cellular polyamines causes selective fragmentation of the TGN and retards secretion of proteins. Since addition of exogenous polyamines reverses these effects, the data indicate that AZIN2 and its downstream effectors, polyamines, are functionally implicated in the regulation of secretory vesicle transport. My studies therefore reveal a novel function for polyamines as modulators of both constitutive and regulated secretion. Based on the results, I propose that the role of AZIN2 is to act as a local in situ activator of polyamine biosynthesis.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The purpose of this work was to elucidate the ontogeny of interleukin-10 (IL-10) secretion from newborn mononuclear cells (MCs), and to examine its relation to the secretion of interferon-g (IFN-g) and immunoglobulins (Igs). The initial hypothesis was that the decreased immunoglobulin (Ig) synthesis of newborn babies was the result of immature cytokine synthesis regulation, which would lead to excessive IL-10 production, leading in turn to suppressed IFN-g secretion. Altogether 57 full-term newborns and 34 adult volunteers were enrolled. Additionally, surface marker compositions of 29 premature babies were included. Enzyme-linked immunoassays were used to determine the amount of secreted IL-10, IFN-g, and Igs, and the surface marker composition of MC were analyzed with a FACScan flow cytometer. The three most important findings were: 1. Cord blood MC, including CD5+ B cells, are able to secrete IL-10. However, when compared with adults, the secretion of IL-10 was decreased. This indicates that reasons other than excessive IL-10 secretion are responsible of reduced IFN-g secretion in newborns. 2. As illustrated by the IL-10 and IFN-g secretion pattern, newborn cytokine profile was skewed towards the Th2 type. However, approximately 25% of newborns had an adult like cytokine profile with both good IL10 and IFN-g secretion, demonstrating that fullterm newborns are not an immunologically homogenous group at the time of birth. 3. There were significant differences in the surface marker composition of MCs between individual neonates. While gestational age correlated with the proportion of some MC types, it is evident that there are many other maternal and fetal factors that influence the maturity and nature of lymphocyte subpopulations in individual neonates. In conclusion, the reduced ability of neonates to secrete Ig and IFN-g is not a consequence of high IL-10 secretion. However, individual newborns differ significantly in their ability to secrete cytokines as well as Igs.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Stroke, ischemic or hemorrhagic, belongs among the foremost causes of death and disability worldwide. Massive brain swelling is the leading cause of death in large hemispheric strokes and is only modestly alleviated by available treatment. Thrombolysis with tissue plasminogen activator (TPA) is the only approved therapy in acute ischemic stroke, but fear of TPA-mediated hemorrhage is often a reason for withholding this otherwise beneficial treatment. In addition, recanalization of the occluded artery (spontaneously or with thrombolysis) may cause reperfusion injury by promoting brain edema, hemorrhage, and inflammatory cell infiltration. A dominant event underlying these phenomena seems to be disruption of the blood-brain barrier (BBB). In contrast to ischemic stroke, no widely approved clinical therapy exists for intracerebral hemorrhage (ICH), which is associated with poor outcome mainly due to the mass effect of enlarging hematoma and associated brain swelling. Mast cells (MCs) are perivascularly located resident inflammatory cells which contain potent vasoactive, proteolytic, and fibrinolytic substances in their cytoplasmic granules. Experiments from our laboratory showed MC density and their state of granulation to be altered early following focal transient cerebral ischemia, and degranulating MCs were associated with perivascular edema and hemorrhage. (I) Pharmacological MC stabilization led to significantly reduced ischemic brain swelling (40%) and BBB leakage (50%), whereas pharmacological MC degranulation raised these by 90% and 50%, respectively. Pharmacological MC stabilization also revealed a 40% reduction in neutrophil infiltration. Moreover, genetic MC deficiency was associated with an almost 60% reduction in brain swelling, 50% reduction in BBB leakage, and 50% less neutrophil infiltration, compared with controls. (II) TPA induced MC degranulation in vitro. In vivo experiments with post-ischemic TPA administration demonstrated 70- to 100-fold increases in hemorrhage formation (HF) compared with controls HF. HF was significantly reduced by pharmacological MC stabilization at 3 (95%), 6 (75%), and 24 hours (95%) of follow-up. Genetic MC deficiency again supported the role of MCs, leading to 90% reduction in HF at 6 and 24 hours. Pharmacological MC stabilization and genetic MC deficiency were also associated with significant reduction in brain swelling and in neutrophil infiltration. Importantly, these effects translated into a significantly better neurological outcome and lower mortality after 24 hours. (III) Finally, in ICH experiments, pharmacological MC stabilization resulted in significantly less brain swelling, diminished growth in hematoma volume, better neurological scores, and decreased mortality. Pharmacological MC degranulation produced the opposite effects. Genetic MC deficiency revealed a beneficial effect similar to that found with pharmacological MC stabilization. In sum, the role of MCs in these clinically relevant scenarios is supported by a series of experiments performed both in vitro and in vivo. That not only genetic MC deficiency but also drugs targeting MCs could modulate these parameters (translated into better outcome and decreased mortality), suggests a potential therapeutic approach in a number of highly prevalent cerebral insults in which extensive tissue injury is followed by dangerous brain swelling and inflammatory cell infiltration. Furthermore, these experiments could hint at a novel therapy to improve the safety of thrombolytics, and a potential cellular target for those seeking novel forms of treatment for ICH.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Cavernomas are rare neurovascular lesions, encountered in up to 10% of patients harboring vascular abnormalities of the CNS. Cavernomas consist of dilated thin-walled sinusoids or caverns covered by a single layer of endothelium. Due to advancements in neuroradiology, the number of cavernoma patients coming to be evaluated in neurosurgical practice is increasing. In the present work, we summarized our results on the treatment of cavernomas. Particular attention was paid to uncommon locations or insufficiently investigated cavernomas, including 1. Intraventricular cavernomas; 2. Multiple cavernomas; 3. Spinal cavernomas; and 4. Temporal lobe cavernomas. After analyzing the patient series with these lesions, we concluded that: 1. IVCs are characterized by a high tendency to cause repetitive hemorrhages in a short period of time after the first event. In most patients, hemorrhages were not life-threatening. Surgery is indicated when re-bleedings are frequent and the mass-effect causes progressive neurological deterioration. Modern microsurgical techniques allow safe removal of the IVC, but surgery on fourth ventricle cavernomas carries increased risk of postoperative cranial nerve deficits. 2. In MC cases, when the cavernoma bleeds or generates drug-resistant epilepsy, microsurgical removal of the symptomatic lesion is beneficial to patients. In our series, surgical removal of the most active cavernoma usually the biggest lesion with signs of recent hemorrhage - was safe and prevented further bleedings. Epilepsy outcome showed the effectiveness of active treatment of MCs. However, due to the remaining cavernomas, epileptogenic activity can persist postoperatively, frequently necessitating long-term use of antiepileptic drugs. 3. Spinal cavernomas can cause severe neurological deterioration due to low tolerance of the spinal cord to mass-effect with progressive myelopathy. When aggravated by extralesional massive hemorrhage, neurological decline is usually acute and requires immediate treatment. Microsurgical removal of a cavernoma is effective and safe, improving neurological deficits. Sensorimotor deficits and pain improved postoperatively at a high rate, whereas bladder dysfunction remained essentially unchanged, causing social discomfort to patients. 4. Microsurgical removal of temporal lobe cavernomas is beneficial for patents suffering from drug-resistant epilepsy. In our series, 69% of patients with this condition became seizure-free postoperatively. Duration of epilepsy did not correlate with seizure prognosis. The most frequent disabling symptom at follow-up was memory disorder, considered to be the result of a complex interplay between chronic epilepsy and possible damage to the temporal lobe during surgery.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A detailed study is presented of the expected performance of the ATLAS detector. The reconstruction of tracks, leptons, photons, missing energy and jets is investigated, together with the performance of b-tagging and the trigger. The physics potential for a variety of interesting physics processes, within the Standard Model and beyond, is examined. The study comprises a series of notes based on simulations of the detector and physics processes, with particular emphasis given to the data expected from the first years of operation of the LHC at CERN.