22 resultados para ubiquitous
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Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014
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Poster at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014
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Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system CNS), where inflammation and neurodegeneration lead to irreversible neuronal damage. In MS, a dysfunctional immune system causes auto‐reactive lymphocytes to migrate into CNS where they initiate an inflammatory cascade leading to focal demyelination, axonal degeneration and neuronal loss. One of the hallmarks of neuronal injury and neuroinflammation is the activation of microglia. Activated microglia are found not only in the focal inflammatory lesions, but also diffusely in the normal‐appearing white matter (NAWM), especially in progressive MS. The purine base, adenosine is a ubiquitous neuromodulator in the CNS and also participates in the regulation of inflammation. The effect of adenosine mediated via adenosine A2A receptors has been linked to microglial activation, whereas modulating A2A receptors may exert neuroprotective effects. In the majority of patients, MS presents with a relapsing disease course, later advancing to a progressive phase characterised by a worsening, irreversible disability. Disease modifying treatments can reduce the severity and progression in relapsing MS, but no efficient treatment exists for progressive MS. The aim of this research was to investigate the prevalence of adenosine A2A receptors and activated microglia in progressive MS by using in vivo positron emission tomography (PET) imaging and [11C]TMSX and [11C](R)‐PK11195 radioligands. Magnetic resonance imaging (MRI) with diffusion tensor imaging (DTI) was performed to evaluate structural brain damage. Non‐invasive input function methods were also developed for the analyses of [11C]TMSX PET data. Finally, histopathological correlates of [11C](R)‐PK11195 radioligand binding related to chronic MS lesions were investigated in post‐mortem samples of progressive MS brain using autoradiography and immunohistochemistry. [11C]TMSX binding to A2A receptors was increased in NAWM of secondary progressive MS (SPMS) patients when compared to healthy controls, and this correlated to more severe atrophy in MRI and white matter disintegration (reduced fractional anisotropy, FA) in DTI. The non‐invasive input function methods appeared as feasible options for brain [11C]TMSX images obviating arterial blood sampling. [11C](R)‐PK11195 uptake was increased in the NAWM of SPMS patients when compared to patients with relapsing MS and healthy controls. Higher [11C](R)‐PK11195 binding in NAWM and total perilesional area of T1 hypointense lesions was associated with more severe clinical disability, increased brain atrophy, higher lesion load and reduced FA in NAWM in the MS patients. In autoradiography, increased perilesional [11C](R)‐PK11195 uptake was associated with increased microglial activation identified using immunohistochemistry. In conclusion, brain [11C]TMSX PET imaging holds promise in the evaluation of diffuse neuroinflammation in progressive MS. Being a marker of microglial activation, [11C](R)‐ PK11195 PET imaging could possibly be used as a surrogate biomarker in the evaluation of the neuroinflammatory burden and clinical disease severity in progressive MS.
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With the new age of Internet of Things (IoT), object of everyday such as mobile smart devices start to be equipped with cheap sensors and low energy wireless communication capability. Nowadays mobile smart devices (phones, tablets) have become an ubiquitous device with everyone having access to at least one device. There is an opportunity to build innovative applications and services by exploiting these devices’ untapped rechargeable energy, sensing and processing capabilities. In this thesis, we propose, develop, implement and evaluate LoadIoT a peer-to-peer load balancing scheme that can distribute tasks among plethora of mobile smart devices in the IoT world. We develop and demonstrate an android-based proof of concept load-balancing application. We also present a model of the system which is used to validate the efficiency of the load balancing approach under varying application scenarios. Load balancing concepts can be apply to IoT scenario linked to smart devices. It is able to reduce the traffic send to the Cloud and the energy consumption of the devices. The data acquired from the experimental outcomes enable us to determine the feasibility and cost-effectiveness of a load balanced P2P smart phone-based applications.
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Työntekijöiden kokema psykologinen omistajuus ja muutokseen suhtautuminen kietoutuvat yhteen tämän tutkimuksen tarkastelussa. Organisaatiot kohtaavat nykypäivänä jatkuvaa muutostarvetta ja työntekijöiden muutokseen suhtautumisella on merkittävä vaikutus muutoshankkeiden onnistuneessa läpiviennissä. Toisaalta työtä kohtaan koetut psykologisen omistajuuden tunteet nähdään merkittävänä työhön ja työn kokemiseen liittyvänä tunteena. Tutkimuksen tavoitteena onkin ymmärtää miten työntekijöiden kokema psykologinen omistajuus ilmenee työntekijöiden muutokseen suhtautumisessa. Tutkimuksen tarkastelu tapahtuu organisatorisessa kontekstissa, merkityksen luomisen viitekehyksessä. Tutkimus suoritettiin fenomenografisena tapaustutkimuksena liiketoiminnan tukipalveluita tarjoavassa asiantuntijaorganisaatiossa. Tutkimuksen lopputuloksen muodostavat neljä erilaista kuvauskategoriaa, jotka kuvaavat kohdeorganisaation työntekijöiden työtään kohtaan kokemia psykologisen omistajuuden tunteita ja sitä kuinka nämä tunteet näyttäytyvät heidän muutokseen suhtautumisessa. Psykologinen omistajuus ja muutokseen suhtautuminen ovat monitahoisia ilmiöitä, joissa yksilön kokemukseen vaikuttavat useat eri tekijät. Psykologista omistajuutta tunteva yksilö on lähtökohtaisesti valmiimpi kohtaamaan muutoksia psykologisen omistajuuden tunteiden ja muutosvalmiuden pohjautuessa monelta osin samoihin tekijöihin. Toisaalta voimakkaat psykologisen omistajuuden tunteet voivat olla yksilöä uuvuttavia, mikä saa muutokset näyttäytymään taakkana myönteisistä aikomuksista huolimatta.
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A tumor is a fast-growing malignant tissue. This creates areas inside the tumor that are distant from local blood vessels to be able to get enough oxygen. This hypoxic condition activates a transcription factor called hypoxia inducible factor (HIF). HIF responses help a cell to adapt to decreased oxygen by activating glycolytic and angiogenesis pathways and by regulating apoptotic responses. Hypoxia drives the upregulation of a growth factor called transforming growth factor beta (TGF-beta). Similar to a hypoxia response, TGF is an important regulator of cell fate. TGF-β and HIF pathways regulate partially overlapping target genes. This regulation can also be cooperative. The TGF-beta signal is initiated by activation of plasma membrane receptors that then activate effector proteins called small mothers against decapentaplegic (Smad) homologs. In healthy tissue, TGF-β keeps cell proliferation and growth under control. During cancer progression, TGF-beta has shown a dual role, whereby it inhibits initial tumor formation but, conversely, in an existent tumor, TGF-beta drives malignant progression. Along with HIF and TGF-beta also protein dephosphorylation is an important regulatory mechanism of cell fate. Protein dephosphorylation is catalyzed by protein phosphatases such as Protein phosphatase 2A (PP2A). PP2A is a ubiquitous phosphatase that can exist in various active forms. PP2A can specifically regulate TGF-beta signaling either by enhancing or inhibiting the receptor activity. This work demonstrates that during hypoxia, PP2A is able to fine-tune TGF-beta signal by specifically targeting Smad3 effector in a Smad7-dependent manner. Inactivation of Smad3 in hypoxia leads to malignant conversion of TGF-beta signaling.
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Humans are profoundly changing aquatic environments through climate change and the release of nutrients and chemicals. To understand the effects of these changes on natural populations, knowledge on individuals’ environmental responses is needed. At the molecular level, the environmental responses are partly mediated by chances in messenger RNA and protein levels. In this thesis I study messenger RNA and protein responses to an assortment of environmental stressors in fish. As daily (diel) rhythms are known to be ubiquitous in different tissues, I particularly focus on diel patterns in the responses. The studied species are the three-spined stickleback (Gasterosteus aculeatus L.) and the Arctic char (Salvelinus alpinus L.), both of which have circumpolar distribution in the Northern hemisphere. In the first two studies, three-spined sticklebacks were exposed to both the non-steroidal anti-inflammatory drug diclofenac and low-oxygen conditions (hypoxia), and their responses measured at separate time points in the liver and gills. The results show how the seemingly unrelated environmental stressors, hypoxia and anti-inflammatory drugs, can have harmful combined effects that differ from the effects of each stressor alone. Moreover, both stressors disturbed natural diel patterns in gene expression. In the third study, I studied the responses of three-spined sticklebacks to two test chemicals: one used in hormonal medicine (17α-ethinyl-oestradiol) and one used as a plasticizer and solvent chemical (di-n-butyl phthalate). The results suggest that the phthalate can affect genes related to spermatogenesis in fish testes, while estrogen-mimicking compounds can lead to numerous disturbances in the endocrine system. In the final study, the temperature-dependence of diel rhythms in messenger RNA levels were evaluated in the liver tissue of the Arctic char, a cold-adapted salmonid. The results show that cold acclimation repressed diel rhythms in gene expression compared to warm-acclimated fish, in which the expression of hundreds of genes was rhythmic, suggesting the circadian clock of the Arctic fish species can be sensitive to temperature. Overall, the results of the thesis indicate that fishes’ responses to abiotic factors interact with their diel rhythms, and more studies on the consequences of these interactions are needed to comprehensively understand human impacts on ecosystems.