12 resultados para Quick-XAS
em Helda - Digital Repository of University of Helsinki
Resumo:
The study approaches two modern novels using the conceptual frame of Lacanian psychoanalysis, especially the Lacanian notion of subject. The novels can be described as subversive “Bildungsromans” (development novels) highly influenced by psychoanalytic thought. Anaïs Nin’s (1903—1977) “poetic novel” House of Incest (1936) is a story of sexual and artistic awakening while Hélène Cixous’s (b. 1937) first novel Dedans (1969) depicts the growth of a little girl whose father dies. Both are first novels and first person narratives. Concentrating in the narrator’s internal life the novels writings break with the realistic conventions of narrative, bringing forth the themes of anguish, alienation from the world and escape into the prison like realm of the self. The study follows roughly the Lacanian process of becoming a subject. Each chapter opens up with a quick introduction to the Lacanian concepts used in the following part that analyses the novels. The study can thus also be used as a brief introduction to Lacanian theory in finnish. The psychoanalytic narrative/story of the birth of the subject and the novels stories can be seen as mirroring each other. The method of the study is thus based on a dialogue between the theoretical concepts and the analyses. Novels are being approached as texts that break with the Cartesian notion of an autonomous subject making room for a dialectics of self and other, for a movement in which the “I” builds an identity mirroring itself with others. While both of the novels recount the birth of a character called I, they also have a first person narrator apart from the character “I”. Having constituted the self’s identity, the narrator finds from inside of the self also an other or “you” – this discovery is the final clue to the coffin of the autonomous self. From the Lacanian perspective man’s great Other is the order of language, Symbolic, which constitutes the individual, the speaking subject. Using this perspective the novels are interpreted as describing the process of becoming a subject of the Symbolic; subjected to Symbolic order. This “birth process” happens in particular in the Imaginary register, where the self’s identity is built. In the Imaginary or Mirror phase the “I” mirrors himself with different others (e.g. with his mirror image and the family members, the surrounding others) learning to see his body and his selfhood both as familiar and strange, other. In the Imaginary phase the novels’ characters are also trying to deal with the opposite realm of the Symcolic, the Real. The Lacanian Real is not the reality “before words” but a reality left over from the Symbolic, aside of it but constituted by the Symbolic, to be deducted only from within it. In the novels the Real is experienced as a womblike state where the self is immersed in the other’s body. The process of coming a subject of the Symbolic is depicted also as a process of renouncing the “dream of the womb”, which, if realized, could only mean the non-existence of the subject, i.e. death. The study concentrates on analysing the novels’ writing, where meanings are constantly changing: “I” becomes you, the father becomes a mother, inside becomes outside. This technique enables also the deconstruction of certain opposing notions in the novels. The Lacanian point of view exposes language as a constantly moving universe where the subject has no more stability than the momentary meanings language creates. The self’s identity depicted in the novels is a Lacanian fixed identity, whose growth is necessary but opposes the flux imminent to the Symbolic. The anguish experienced in the novels, in the “house of incest” or “inside”, is due to clinging on the unchanging “I”. However, the writing of the novels shows how the meaning of the “I” changes constantly and the fixity thus becomes movement. This way House of Incest and Dedans, despite their pessimistic stories, manage to create an image of a new, moving subject.
Resumo:
Haptices and haptemes: A case study of developmental process in touch-based communication of acquired deafblind people This research is the first systematic, longitudinal process and development description of communication using touch and body with an acquired deafblind person. The research consists of observational and analysed written and video materials mainly from two informants´ experiences during period of 14 years. The research describes the adaptation of Social-Haptic methods between a couple, and other informants´ experiences, which have been collated from biographies and through giving national and international courses. When the hearing and sight deteriorates due to having an acquired deafblind condition, communication consists of multi-systematic and adaptive methods. A person`s expressive language, spoken or Sign Language, usually remains unchanged, but the methods of receiving information could change many times during a person s lifetime. Haptices are made from haptemes that determines which regulations are analysed. When defining haptemes the definition, classification and varied meanings of touch were discovered. Haptices include sharing a personal body space, meaning of touch-contact, context and using different communication channels. Communication distances are classified as exact distance, estimated distance and touch distance. Physical distance can be termed as very long, long, medium or very close. Social body space includes the body areas involved in sending and receiving haptices and applying different types of contacts. One or two hands can produce messages by using different hand shapes and orientations. This research classifies how the body can be identified into different areas such as body orientation, varied body postures, body position levels, social actions and which side of the body is used. Spatial body space includes environmental and situational elements. Haptemes of movements are recognised as the direction of movements, change of directions on the body, directions between people, pressure, speed, frequency, size, length, duration, pause, change of rhythm, shape, macro and micro movements. Haptices share multidimensional meanings and emotions. Research describes haptices in different situations enhancing sensory information and functioning also as an independent language. Haptices includes social-haptic confirmation system, social quick messages, body drawing, contact to the people and the environment, guiding and sharing art experiences through movements. Five stages of emotional differentiation were identified as very light, light, medium, heavy and very heavy touch. Haptices give the possibility to share different art, hobby and game experiences. A new communication system development based on the analysis of the research data is classified into different phases. These are experimental initiation, social deconstruction, developing the description of Social-Haptic communication and generalisation of the theory as well as finding and conceptualising the haptices and haptemes. The use and description of haptices is a social innovation, which illustrates the adaptive function of the body and perceptual senses that can be taught to a third party. Keywords: deafblindness, hapteme, haptic, haptices, movement, social-haptic communication, social-haptic confirmation system, tactile, touch
Resumo:
Probiooteilla kantakohtaisia vaikutuksia ihmisen immuunijärjestelmään terveillä aikuisilla Probiooteilla on kantakohtaisia tulehduksen välittäjäaineita vähentäviä vaikutuksia ja probioottien yhdistelmien vaikutukset eroavat yksittäisten kantojen vaikutuksista selviää TtM Riina Kekkosen tuoreesta väitöstutkimuksesta. TtM Riina Kekkonen on selvittänyt väitöskirjassaan eri probioottikantojen vaikutuksia immuunivasteeseen valkosolumallissa sekä terveillä aikuisilla lumekontrolloiduissa kliinisissä tutkimuksissa. Aikaisemmin probioottien vaikutuksia on tutkittu lähinnä allergian ja erilaisten vatsavaivojen ehkäisyssä ja hoidossa. Probiootteja sisältäviä tuotteita käyttävät kuluttajat ovat kuitenkin useimmiten terveitä aikuisia, ja probioottien vaikutus terveiden aikuisten immuunijärjestelmään on ollut puutteellisesti selvitettyä. Valkosolumallissa probioottikantojen havaittiin poikkeavan toisistaan niiden kyvyssä aktivoida immuunivasteen välittäjäaineiden, sytokiinien, tuotantoa. Anti-inflammatorisia, eli tulehdusta lievittäviä vaikutuksia nähtiin lähinnä Bifidobacterium ja Propionibacterium sukuihin kuuluvilla kannoilla. Streptococcus ja Leuconostoc sukuihin kuuluvat kannat puolestaan aktivoivat Th1 tyyppistä, soluvälitteistä immuunivastetta. Eri probioottien kombinaatiot eivät saaneet aikaan voimakkaampaa aktivaatiota yksittäisiin kantoihin verrattuna, joka viittaa probioottien keskinäiseen kilpailuun niiden ollessa kontaktissa ihmisen solujen kanssa. Probioottikantojen valinta kliinisiin tutkimuksiin tehtiin niiden anti-inflammatoristen ominaisuuksien perusteella. Parhaita anti-inflammatorisia kantoja olivat B. lactis ssp. animalis Bb12 ja P. freudenreichii ssp. shermanii JS, joiden lisäksi tutkimuksiin valittiin myös L. rhamnosus GG (LGG) hyvin tutkittuna referenssikantana. Solutöiden tulokset eivät olleet täysin verrannollisia kliinisen työn tuloksiin, koska LGG näytti omaavan parhaat anti-inflammatoriset ominaisuudet kliinisissä tutkimuksissa vaikka solutyössä sen aikaansaamat vasteet olivat melko vaimeita. Kolmen viikon kliinisessä tutkimuksessa terveillä aikuisilla LGG alensi mm. tulehdusta kuvaavan C-reaktiivisen proteiinin ja inflammatoristen sytokiinien määrää. Pidemmässä kolmen kuukauden pituisessa kliinisessä tutkimuksessa LGG:llä ei ollut vaikutusta terveiden aikuisten infektiosairastavuuteen, mutta LGG lyhensi vatsavaivojen kestoa. Probioottien vaikutukset immuunijärjestelmään näyttävät olevan kantakohtaisia ja erityisesti Lactobacillus rhamnosus GG:llä havaittiin anti-inflammatorisia vaikutuksia. Valkosolumallia ei tulisi käyttää ainoana probioottikantojen skriinausmenetelmänä niiden immunologisia vaikutuksia selvitettäessä, koska solutöiden tulokset eivät olleet täysin verrannollisia kliinisten tutkimusten tuloksiin. Sen sijaan veren perifeeristen lymfosyyttien eristäminen ja niiden aktivoitumisen selvittäminen lyhytaikaisessa kliinisessä tutkimuksessa voisi toimia suhteellisen helppona skiinausmenetelmänä.
Resumo:
The studies presented in this thesis contribute to the understanding of evolutionary ecology of three major viruses threatening cultivated sweetpotato (Ipomoea batatas Lam) in East Africa: Sweet potato feathery mottle virus (SPFMV; genus Potyvirus; Potyviridae), Sweet potato chlorotic stunt virus (SPCSV; genus Crinivirus; Closteroviridae) and Sweet potato mild mottle virus (SPMMV; genus Ipomovirus; Potyviridae). The viruses were serologically detected and the positive results confirmed by RT-PCR and sequencing. SPFMV was detected in 24 wild plant species of family Convolvulacea (genera Ipomoea, Lepistemon and Hewittia), of which 19 species were new natural hosts for SPFMV. SPMMV and SPCSV were detected in wild plants belonging to 21 and 12 species (genera Ipomoea, Lepistemon and Hewittia), respectively, all of which were previously unknown to be natural hosts of these viruses. SPFMV was the most abundant virus being detected in 17% of the plants, while SPMMV and SPCSV were detected in 9.8% and 5.4% of the assessed plants, respectively. Wild plants in Uganda were infected with the East African (EA), common (C), and the ordinary (O) strains, or co-infected with the EA and the C strain of SPFMV. The viruses and virus-like diseases were more frequent in the eastern agro-ecological zone than the western and central zones, which contrasted with known incidences of these viruses in sweetpotato crops, except for northern zone where incidences were lowest in wild plants as in sweetpotato. The NIb/CP junction in SPMMV was determined experimentally which facilitated CP-based phylogenetic and evolutionary analyses of SPMMV. Isolates of all the three viruses from wild plants were genetically similar to those found in cultivated sweetpotatoes in East Africa. There was no evidence of host-driven population genetic structures suggesting frequent transmission of these viruses between their wild and cultivated hosts. The p22 RNA silencing suppressor-encoding sequence was absent in a few SPCSV isolates, but regardless of this, SPCSV isolates incited sweet potato virus disease (SPVD) in sweetpotato plants co-infected with SPFMV, indicating that p22 is redundant for synergism between SCSV and SPFMV. Molecular evolutionary analysis revealed that isolates of strain EA of SPFMV that is largely restricted geographically in East Africa experience frequent recombination in comparison to isolates of strain C that is globally distributed. Moreover, non-homologous recombination events between strains EA and C were rare, despite frequent co-infections of these strains in wild plants, suggesting purifying selection against non-homologous recombinants between these strains or that such recombinants are mostly not infectious. Recombination was detected also in the 5 - and 3 -proximal regions of the SPMMV genome providing the first evidence of recombination in genus Ipomovirus, but no recombination events were detected in the characterized genomic regions of SPCSV. Strong purifying selection was implicated on evolution of majority of amino acids of the proteins encoded by the analyzed genomic regions of SPFMV, SPMMV and SPCSV. However, positive selection was predicted on 17 amino acids distributed over the whole the coat protein (CP) in the globally distributed strain C, as compared to only 4 amino acids in the multifunctional CP N-terminus (CP-NT) of strain EA largely restricted geographically to East Africa. A few amino acid sites in the N-terminus of SPMMV P1, the p7 protein and RNA silencing suppressor proteins p22 and RNase3 of SPCSV were also submitted to positive selection. Positively selected amino acids may constitute ligand-binding domains that determine interactions with plant host and/or insect vector factors. The P1 proteinase of SPMMV (genus Ipomovirus) seems to respond to needs of adaptation, which was not observed with the helper component proteinase (HC-Pro) of SPMMV, although the HC-Pro is responsible for many important molecular interactions in genus Potyvirus. Because the centre of origin of cultivated sweetpotato is in the Americas from where the crop was dispersed to other continents in recent history (except for the Australasia and South Pacific region), it would be expected that identical viruses and their strains occur worldwide, presuming virus dispersal with the host. Apparently, this seems not to be the case with SPMMV, the strain EA of SPFMV and the strain EA of SPCSV that are largely geographically confined in East Africa where they are predominant and occur both in natural and agro-ecosystems. The geographical distribution of plant viruses is constrained more by virus-vector relations than by virus-host interactions, which in accordance of the wide range of natural host species and the geographical confinement to East Africa suggest that these viruses existed in East African wild plants before the introduction of sweetpotato. Subsequently, these studies provide compelling evidence that East Africa constitutes a cradle of SPFMV strain EA, SPCSV strain EA, and SPMMV. Therefore, sweet potato virus disease (SPVD) in East Africa may be one of the examples of damaging virus diseases resulting from exchange of viruses between introduced crops and indigenous wild plant species. Keywords: Convolvulaceae, East Africa, epidemiology, evolution, genetic variability, Ipomoea, recombination, SPCSV, SPFMV, SPMMV, selection pressure, sweetpotato, wild plant species Author s Address: Arthur K. Tugume, Department of Agricultural Sciences, Faculty of Agriculture and Forestry, University of Helsinki, Latokartanonkaari 7, P.O Box 27, FIN-00014, Helsinki, Finland. Email: tugume.arthur@helsinki.fi Author s Present Address: Arthur K. Tugume, Department of Botany, Faculty of Science, Makerere University, P.O. Box 7062, Kampala, Uganda. Email: aktugume@botany.mak.ac.ug, tugumeka@yahoo.com
Resumo:
The TCP protocol is used by most Internet applications today, including the recent mobile wireless terminals that use TCP for their World-Wide Web, E-mail and other traffic. The recent wireless network technologies, such as GPRS, are known to cause delay spikes in packet transfer. This causes unnecessary TCP retransmission timeouts. This dissertation proposes a mechanism, Forward RTO-Recovery (F-RTO) for detecting the unnecessary TCP retransmission timeouts and thus allow TCP to take appropriate follow-up actions. We analyze a Linux F-RTO implementation in various network scenarios and investigate different alternatives to the basic algorithm. The second part of this dissertation is focused on quickly adapting the TCP's transmission rate when the underlying link characteristics change suddenly. This can happen, for example, due to vertical hand-offs between GPRS and WLAN wireless technologies. We investigate the Quick-Start algorithm that, in collaboration with the network routers, aims to quickly probe the available bandwidth on a network path, and allow TCP's congestion control algorithms to use that information. By extensive simulations we study the different router algorithms and parameters for Quick-Start, and discuss the challenges Quick-Start faces in the current Internet. We also study the performance of Quick-Start when applied to vertical hand-offs between different wireless link technologies.
Resumo:
Individuals face variable environmental conditions during their life. This may be due to migration, dispersion, environmental changes or, for example, annual variation in weather conditions. Genetic adaptation to a novel environment happens through natural selection. Phenotypic plasticity allows, however, a quick individual response to a new environment. Phenotypic plasticity may also be beneficial for individual if the environment is highly variable. For example, eggs are costly to produce. If the food conditions vary significantly between breeding seasons it is useful to be able to adjust the clutch and egg size according to the food abundance. In this thesis I use Ural owl vole system to study phenotypic plasticity and natural selection using a number of reproduction related traits. The Ural owl (Strix uralensis) is a long-lived and sedentary species. The reproduction and survival of the Ural owl, in fact their whole life, is tied to the dramatically fluctuating vole densities. Ural owls do not cause vole cycles but they have to adjust their behaviour to the rather predictable population fluctuations of these small mammals. Earlier work with this system has shown that Ural owl laying date and clutch size are plastic in relation to vole abundance. Further, individual laying date clutch size reaction norms have been shown to vary in the amount of plasticity. My work extends the knowledge of natural selection and phenotypic plasticity in traits related to reproduction. I show that egg size, timing of the onset of incubation and nest defense aggressiveness are plastic traits with fitness consequences for the Ural owl. Although egg size is in general thought to be a fixed characteristic of an individual, this highly heritable trait in the Ural owl is also remarkably plastic in relation to the changes in vole numbers, Ural owls are laying the largest eggs when their prey is most abundant. Timing of the onset of incubation is an individual-specific property and plastic in relation to clutch size. Timing of incubation is an important underlying cause for asynchronous hatching in birds. Asynchronous hatching is beneficial to offspring survival in Ural owl. Hence, timing of the onset of incubation may also be under natural selection. Ural owl females also adjust their nest defense aggressiveness according to the vole dynamics, being most aggressive in years when they produce the largest broods. Individual females show different levels of nest defense aggressiveness. Aggressiveness is positively correlated with the phenotypic plasticity of aggressiveness. As elevated nest defense aggressiveness is selected for, it may promote the plasticity of aggressive nest defense behaviour. All the studied traits are repeatable or heritable on individual level, and their expression is either directly or indirectly sensitive to changes in vole numbers. My work considers a number of important fitness-related traits showing phenotypic plasticity in all of them. Further, in two chapters I show that there is individual variation in the amount of plasticity exhibited. These findings on plasticity in reproduction related traits suggest that variable environments indeed promote plasticity.
Resumo:
The juvenile sea squirt wanders through the sea searching for a suitable rock or hunk of coral to cling to and make its home for life. For this task it has a rudimentary nervous system. When it finds its spot and takes root, it doesn't need its brain any more so it eats it. It's rather like getting tenure. Daniel C. Dennett (from Consciousness Explained, 1991) The little sea squirt needs its brain for a task that is very simple and short. When the task is completed, the sea squirt starts a new life in a vegetative state, after having a nourishing meal. The little brain is more tightly structured than our massive primate brains. The number of neurons is exact, no leeway in neural proliferation is tolerated. Each neuroblast migrates exactly to the correct position, and only a certain number of connections with the right companions is allowed. In comparison, growth of a mammalian brain is a merry mess. The reason is obvious: Squirt brain needs to perform only a few, predictable functions, before becoming waste. The more mobile and complex mammals engage their brains in tasks requiring quick adaptation and plasticity in a constantly changing environment. Although the regulation of nervous system development varies between species, many regulatory elements remain the same. For example, all multicellular animals possess a collection of proteoglycans (PG); proteins with attached, complex sugar chains called glycosaminoglycans (GAG). In development, PGs participate in the organization of the animal body, like in the construction of parts of the nervous system. The PGs capture water with their GAG chains, forming a biochemically active gel at the surface of the cell, and in the extracellular matrix (ECM). In the nervous system, this gel traps inside it different molecules: growth factors and ECM-associated proteins. They regulate the proliferation of neural stem cells (NSC), guide the migration of neurons, and coordinate the formation of neuronal connections. In this work I have followed the role of two molecules contributing to the complexity of mammalian brain development. N-syndecan is a transmembrane heparan sulfate proteoglycan (HSPG) with cell signaling functions. Heparin-binding growth-associated molecule (HB-GAM) is an ECM-associated protein with high expression in the perinatal nervous system, and high affinity to HS and heparin. N-syndecan is a receptor for several growth factors and for HB-GAM. HB-GAM induces specific signaling via N-syndecan, activating c-Src, calcium/calmodulin-dependent serine protein kinase (CASK) and cortactin. By studying the gene knockouts of HB-GAM and N-syndecan in mice, I have found that HB-GAM and N-syndecan are involved as a receptor-ligand-pair in neural migration and differentiation. HB-GAM competes with the growth factors fibriblast growth factor (FGF)-2 and heparin-binding epidermal growth factor (HB-EGF) in HS-binding, causing NSCs to stop proliferation and to differentiate, and affects HB-EGF-induced EGF receptor (EGFR) signaling in neural cells during migration. N-syndecan signaling affects the motility of young neurons, by boosting EGFR-mediated cell migration. In addition, these two receptors form a complex at the surface of the neurons, probably creating a motility-regulating structure.
Resumo:
The greatest effect on reducing mortality in breast cancer comes from the detection and treatment of invasive cancer when it is as small as possible. Although mammography screening is known to be effective, observer errors are frequent and false-negative cancers can be found in retrospective studies of prior mammograms. In the year 2001, 67 women with 69 surgically proven cancers detected at screening in the Mammography Centre of Helsinki University Hospital had previous mammograms as well. These mammograms were analyzed by an experienced screening radiologist, who found that 36 lesions were already visible in previous screening rounds. CAD (Second Look v. 4.01) detected 23 of these missed lesions. Eight readers with different kinds of experience with mammography screening read the films of 200 women with and without CAD. These films included 35 of those missed lesions and 16 screen-detected cancers. CAD sensitivity was 70.6% and specificity 15.8%. Use of CAD lengthened the mean time spent for readings but did not significantly affect readers sensitivities or specificities. Therefore the use of applied version of CAD (Second Look v. 4.01) is questionable. Because none of those eight readers found exactly same cancers, two reading methods were compared: summarized independent reading (at least a single cancer-positive opinion within the group considered decisive) and conference consensus reading (the cancer-positive opinion of the reader majority was considered decisive). The greatest sensitivity of 74.5% was achieved when the independent readings of 4 best-performing readers were summarized. Overall the summarized independent readings were more sensitive than conference consensus readings (64.7% vs. 43.1%) while there was far less difference in mean specificities (92.4% vs. 97.7%). After detecting suspicious lesion, the radiologist has to decide what is the most accurate, fast, and cost-effective means of further work-up. The feasibility of FNAC and CNB in the diagnosis of breast lesions was compared in non-randomised, retrospective study of 580 (503 malignant) breast lesions of 572 patients. The absolute sensitivity for CNB was better than for FNAC, 96% (206/214) vs. 67% (194/289) (p < 0.0001). An additional needle biopsy or surgical biopsy was performed for 93 and 62 patients with FNAC, but for only 2 and 33 patients with CNB. The frequent need of supplement biopsies and unnecessary axillary operations due to false-positive findings made FNAC (294 ) more expensive than CNB (223 ), and because the advantage of quick analysis vanishes during the overall diagnostic and referral process, it is recommendable to use CNB as initial biopsy method.
Resumo:
Triggered by the very quick proliferation of Internet connectivity, electronic document management (EDM) systems are now rapidly being adopted for managing the documentation that is produced and exchanged in construction projects. Nevertheless there are still substantial barriers to the efficient use of such systems, mainly of a psychological nature and related to insufficient training. This paper presents the results of empirical studies carried out during 2002 concerning the current usage of EDM systems in the Finnish construction industry. The studies employed three different methods in order to provide a multifaceted view of the problem area, both on the industry and individual project level. In order to provide an accurate measurement of overall usage volume in the industry as a whole telephone interviews with key personnel from 100 randomly chosen construction projects were conducted. The interviews showed that while around 1/3 of big projects already have adopted the use of EDM, very few small projects have adopted this technology. The barriers to introduction were investigated through interviews with representatives for half a dozen of providers of systems and ASP-services. These interviews shed a lot of light on the dynamics of the market for this type of services and illustrated the diversity of business strategies adopted by vendors. In the final study log files from a project which had used an EDM system were analysed in order to determine usage patterns. The results illustrated that use is yet incomplete in coverage and that only a part of the individuals involved in the project used the system efficiently, either as information producers or consumers. The study also provided feedback on the usefulness of the log files.
Resumo:
Tutkielmassa tarkastellaan kuluttajien näkemyksiä ilmastonmuutoksesta ja ilmastovaikutusten seuranta- ja palautejärjestelmän hyväksyttävyydestä kulutuksen ohjauskeinona. 15 kuluttajaa kokeili kuukauden ajan kulutuksen ilmastovaikutusten seuranta- ja palautejärjestelmän demonstraatioversiota ja he osallistuivat kokeilun pohjalta aihepiiriä käsitelleeseen verkkokeskusteluun. Analysoin verkkokeskustelun aineistoa arkisen järkeilyn näkökulmasta tutkien kuluttajien ilmastonmuutokseen ja ympäristövastuullisuuteen liittyvää arkitietoa sekä palvelun hyväksyttävyyteen liittyviä heuristiikkoja. Ilmastonmuutoksen todettiin yleisesti olevan vielä melko abstrakti ja monitulkintainen ilmiö, minkä vuoksi kuluttajilla on vaikeuksia ymmärtää omien valintojensa konkreettista merkitystä ilmastonmuutoksen kannalta. Vaikka tietoa kulutuksen ilmastovaikutuksista on saatavilla paljon, niin erityisesti yritysten tuottama tieto koettiin ristiriitaiseksi ja osin epäluotettavaksi. Kuluttajat myös kritisoivat ilmastonmuutoskeskustelun tarjoamaa kapeaa näkemystä kulutuksen ympäristövaikutuksista. Hiilidioksidipäästöihin keskittymisen sijaan ympäristövaikutuksia tulisi kuluttajien mielestä tarkastella kokonaisuutena, josta ilmastovaikutukset muodostavat vain yhden osan. Tutkimukseen osallistuneiden kuluttajien kulutustottumuksiin ilmastonmuutos vaikutti eriasteisesti. Toisille ilmastonmuutoksesta oli muodostunut keskeinen omaa kulutusta ohjaava normi, kun taas toiset kertoivat pohtivansa ilmastovaikutuksia pääasiassa suurimpien hankintojen kohdalla. Ympäristövastuullisuudessa merkitykselliseksi koettiin tasapainon löytäminen ja henkilökohtainen tunne siitä, että kokee toimivansa oikein. Ilmasto- tai ympäristökysymyksiä punnitaan valinnoissa joustavasti yhdessä muiden tekijöiden kanssa. Vaikka kuluttajilla toisaalta olisi tietoa ja halua ottaa ilmasto- ja ympäristövaikutukset huomioon valinnoissaan, toimintaympäristö rajaa keskeisesti kuluttajien mahdollisuuksia toimia ympäristövastuullisesti. Tutkimus toi esille neljä kuluttajien käyttämää heuristiikkaa heidän pohtiessaan ilmastovaikutusten seuranta- ja palautejärjestelmän hyväksyttävyyden ehtoja ja toimivuutta ohjauskeinona. Ensinnäkin palvelun tulee olla käytettävyydeltään nopea ja vaivaton sekä tarjota tietoa havainnollisessa ja helposti ymmärrettävässä muodossa. Toiseksi palvelun tarjoaman tiedon tulee olla ehdottoman luotettavaa ja kuluttajien valintojen kannalta merkityksellistä siten, että palvelu ottaa huomioon erilaiset kuluttajat ja tiedontarpeet. Kolmanneksi palvelu tulee toteuttaa kokonaisvaltaisesti ja läpinäkyvästi useampien kaupparyhmittymien ja julkisten toimijoiden yhteistyönä. Neljänneksi toteutuksessa tulee huomioda palvelun kannustavuus ja kytkeytyminen muihin ohjauskeinoihin.
Resumo:
X-ray synchrotron radiation was used to study the nanostructure of cellulose in Norway spruce stem wood and powders of cobalt nanoparticles in cellulose support. Furthermore, the growth of metallic clusters was modelled and simulated in the mesoscopic size scale. Norway spruce was characterized with x-ray microanalysis at beamline ID18F of the European Synchrotron Radiation Facility in Grenoble. The average dimensions and the orientation of cellulose crystallites was determined using x-ray microdiffraction. In addition, the nutrient element content was determined using x-ray fluorescence spectroscopy. Diffraction patterns and fluorescence spectra were simultaneously acquired. Cobalt nanoparticles in cellulose support were characterized with x-ray absorption spectroscopy at beamline X1 of the Deutsches Elektronen-Synchrotron in Hamburg, complemented by home lab experiments including x-ray diffraction, electron microscopy and measurement of magnetic properties with a vibrating sample magnetometer. Extended x-ray absorption fine structure spectroscopy (EXAFS) and x-ray diffraction were used to solve the atomic arrangement of the cobalt nanoparticles. Scanning- and transmission electron microscopy were used to image the surfaces of the cellulose fibrils, where the growth of nanoparticles takes place. The EXAFS experiment was complemented by computational coordination number calculations on ideal spherical nanocrystals. The growth process of metallic nanoclusters on cellulose matrix is assumed to be rather complicated, affected not only by the properties of the clusters themselves, but essentially depending on the cluster-fiber interfaces as well as the morphology of the fiber surfaces. The final favored average size for nanoclusters, if such exists, is most probably a consequence of these two competing tendencies towards size selection, one governed by pore sizes, the other by the cluster properties. In this thesis, a mesoscopic model for the growth of metallic nanoclusters on porous cellulose fiber (or inorganic) surfaces is developed. The first step in modelling was to evaluate the special case of how the growth proceeds on flat or wedged surfaces.
Resumo:
In recent years urban hydrology and individual urban streams have been in focus and subjects to research also in Helsinki. However, until now there has been lack of research covering simultaneously the whole area of the city of Helsinki. The aim of this study was to find out the general state of water quality in small urban streams in the city of Helsinki. 21 streams were studied: Mätäjoki, Korppaanoja, Mätäpuro, Näsinoja-Tuomarinkylänoja, Tuomarinkartanonpuro, Kumpulanpuro, Tapaninkylänpuro, Tapaninvainionpuro, Puistolanpuro, Longinoja, Säynäslahdenpuro, Viikinoja, Porolahdenpuro, Mustapuro, Marjaniemenpuro, Mellunkylänpuro, Vuosaarenpuro, Rastilanpuro, Ramsinkannaksenpuro, Skatanpuro and Yliskylänpuro. Water samples were collected from 48 sampling points, each stream having at least one point. Four water samples were collected from each point, sampling periods being 9.-11.2., 26.-28.4., 29.6.-1.7. and 25.-27.10.2004. Field measurements associated with water sampling included water temperature, oxygen concentration, pH and electrical conductivity. Water samples were analysed in the Laboratory of Physical Geography in the University of Helsinki and in the Environmental Laboratory of the City of Helsinki Environment Centre for following properties: suspended solids, dissolved substances, alkalinity, principal anions and cations (Na+, K+, Mg2+, Ca2+, F-, Cl-, NO3-, PO43- and SO42-), colour, turbidity, biological and chemical oxygen demand (BOD7 and CODMn-values), nutrient concentrations and bacterial indicators of hygienic quality. The main water quality issues found in this study were low oxygen levels in many streams and poor hygienic quality at least occasionally. E.g. in summer oxygen levels were under 60 % in every stream. Amount of total dissolved substances and nutrients were high in some of the streams studied. Compared to other Finnish streams the values of alkalinity and pH were higher. Although these problems were common, the variation between different streams and sampling points was significant. This was probably due to local conditions. Best overall water quality was found in Mätäpuro and Tuomarinkartanonpuro streams. Seasonal variation was evident in almost all water quality properties. For example the total amount of dissolved substances was largest in winter and decreased during the year. Colour and turbidity were smallest in winter and increased towards the end of the year. The same was true for suspended solids, which had smallest concentration in winter and greatest in autumn. It must be kept in mind that the spring samples were collected after the spring flood otherwise the largest suspended solid concentrations would have been expected in spring. Finnish general water quality classification was used to assess the quality of urban stream waters. Its suitability for small urban streams is not, however, completely trouble-free. This classification does not take into account the quick changes in such small streams but evaluates only the yearly mean values. This can oversimplify the picture of the water quality situation in the streams. Also in order to better reflect the urban environment the analysed water quality properties should also include total dissolved substances and e.g. concentrations of chloride and sodium.