E-thesis

Recent Submissions

  • Neittaanmäki, Eerika (2015)
    Aktiinikeratoosit ovat auringon UV-säteilyn aiheuttamia ihosyövän esiasteita iholla. Hoitamattomana osa näistä muutoksista kehittyy vuosien kuluessa invasiivisiksi okasolusyöviksi. Aktiinikeratoosit ovat maailmanlaajuisesti yleistyvä ja terveydenhuoltoa kuormittava ongelma. Aktiinikeratooseista ja niitä ympäröiviltä ihoalueilta löydetään usein p53-geenin mutaatioita. Hoitovaihtoehtoja ovat leikkaus, jäädytyshoito, erilaiset paikallishoitovoiteet kuten immuunivasteen muuntajat sekä fotodynaaminen hoito (PDT). Aminolevuliinihappo (ALA) on PDT-hoidossa käytetty porfyriinirakenteinen endogeeninen valoherkistäjä, josta on kehitetty myös johdannaiset metyyliaminolevulinaatti (MAL) ja heksyyliaminolevulinaatti (HAL). Valoherkistäjän altistuminen valolle saa aikaan valokemiallisen reaktion ja kasvainsolujen tuhoutumisen. Valonlähteenä PDT-hoidossa voidaan käyttää keinovaloa tai päivänvaloa. Fotodynaaminen hoidon yleisimmät haittavaikutukset ovat kipu ja hoitoalueen punoitus. Etuja ovat hyvä kosmeettinen tulos ja mahdollisuus hoitaa laajoja leesioalueita. Erikoistyön kokeellisessa osassa tutkittiin valoherkistäjien (BF-200 ALA, MAL, HAL 2 % ja 0,2) vaikutusta terveillä vapaehtoisilla. Valonlähteenä käytettiin punaista keinovaloa. Tutkimuksessa vertailtiin yhdisteiden aiheuttamaa kipua, ihoärsytystä ja fluoresenssia terveellä iholla. Fluoresenssin voimakkuus kuvaa valoherkistäjän tehoa tuottaa PpIX:ä. Kokeellisen osan toisena osatyönä oli osallistuminen kliiniseen lääketutkimukseen, jossa verrattiin BF-200 ALA- ja MAL-valoherkistäjien käytettävyyttä aktiinikeratoosien päivänvalo-PDT:ssä. Jokainen potilas sai kumpaakin valoherkistäjää pään eri puolille. Tulokset arvioitiin 3 kuukauden kuluttua. Terveellä iholla BF-200 ALA, MAL ja HAL 2 % aiheuttivat enemmän ärsytystä ja suuremman fluoresenssin kuin HAL 0,2 %. HAL 2 % ei eronnut BF-200 ALA- ja MAL-ryhmistä reaktioiden vahvuuden, punoituksen eikä fluoresenssin suhteen. Kipu oli kuitenkin pienempää HAL- kuin ALA ja MAL- ryhmissä. Ihomuutoksissa eri valoherkistäjän imeytyminen, jakautuminen ja PpIX:n tuotanto voivat kuitenkin olla erilaista kuin terveellä iholla. BF-200 ALA ja MAL olivat molemmat tehokkaita aktiinikeratoosien päivänvalohoidossa. Hoidon tehossa tai sen aiheuttamassa kivussa ei ollut eroa ryhmien välillä. Pitkäaikaistuloksia tarvitaan kuitenkin varmistamaan hoitotulosten säilyminen.
  • Koskela, Jaana (2015)
    Mekanofuusio on kuivapäällystysmenetelmä, jossa suuret leikkausvoimat saavat aikaan mekaaniskemiallisen reaktion prosessoitavien partikkelien välillä. Menetelmän avulla kohesiivisten jauhemassojen valuvuutta on voitu parantaa kuivapäällystämällä massa magnesiumstearaatilla. Huonosti valuvien suuriannoksisten lääkeaineiden soveltuvuutta suorapuristukseen voitaisiinkin parantaa mekanofuusion avulla. Magnesiumstearaatin tiedetään kuitenkin heikentävän tablettien lujuutta, pidentävän tabletin hajoamisaikaa sekä hidastavan dissoluutiota. Aikaisemmassa tutkimuksessa magnesiumstearaatilla kuivapäällystetystä formulaatiosta oli kuitenkin mahdollista puristaa tabletteja ilman dissoluution hidastumista. Tutkimusta mekanofuusiosta magnesiumstearaatilla ja sen vaikutuksesta tabletoitavaan massaan ei kuitenkaan ole tehty plastiselle materiaalille, joka on herkkä magnesiumstearaatin negatiivisille vaikutuksille. Tutkimuksen tarkoituksena oli selvittää, miten kuivapäällystys magnesiumstearaatilla vaikuttaa plastisen materiaalin fysikaalisiin ominaisuuksiin ja puristumiskäyttäytymiseen. Ilmiötä tarkasteltiin kuivapäällystämällä neljän eri partikkelikoon mikrokiteistä selluloosaa eri magnesiumstearaattipitoisuuksilla. Tavoitteena oli löytää optimi massan valuvuuden ja puristuvuuden välille prosessiparametreja muuttamalla. Tutkimuksessa haluttiin myös selvittää, vaikuttaako mekanofuusio itsessään mikrokiteisen selluloosan ominaisuuksiin ja kahta raaka-ainetta (D50 23 ja 78 μm) mekanofuusioitiin ilman magnesiumstearaattia. Verrokkeina käytettiin puhtaita raaka-aineita sekä Turbula-sekoitettuja magnesiumstearaatin ja mikrokiteisen selluloosan seoksia. Kuivapäällystys magnesiumstearaatilla paransi massojen valuvuutta, kun mikrokiteisen selluloosan D50-arvo oli alle 78 μm. Kun massojen D50-arvo oli yli 144 μm, valuvuus kuitenkin huonontui, mikä johtui partikkelien hajoamisesta mekanofuusioitaessa. Voidaankin arvioida, että mekanofuusio prosessina soveltuu vain mikrokiteiselle selluloosalle, jolla on pieni partikkelikoko ja jonka partikkelit kestävät paremmin suuria leikkausvoimia. Kun mikrokiteistä selluloosaa (D50 78 μm) mekanofuusioitiin ilman magnesiumstearaattia, massan kosteuspitoisuuden havaittiin nousseen ja massasta saatiin puristettua lujempia tabletteja. Mekanofuusio saattaa vaikuttaa mikrokiteisen selluloosan mikrorakenteeseen ja siten myös kykyyn sitoa kosteutta itseensä. Kuivapäällystys magnesiumstearaatilla puolestaan oli hyvin tehokasta jo pienillä kierrosnopeuksilla ja lyhyellä prosessiajalla, ja mekanofuusioiduista massoista oli haastavaa saada aikaan lujia tabletteja. Plastisen materiaalin todettiin olevan herkkä magnesiumstearaatin negatiivisille vaikutuksille, ja mitä parempi valuvuus mekanofuusioidulla massalla oli, sitä heikompia tabletteja saatiin puristettua.
  • Virta, Sanna-Mari (2015)
    Hoitovaihtoehto hampaattomille potilaille on irrotettava kokoproteesi, jolla on usein heikko stabiliteetti ja retentio alveoliharjanteen jatkuvan resorption vuoksi. Retention ja stabiliteetin lisäämiseksi voidaan käyttää implantteja, mutta toisinaan olosuhteet perinteisille implanteille ovat rajoitetut. Tällöin on mahdollista käyttää halkaisijaltaan pienempiä mini-implantteja. Ne mahdollistavat kokoproteesin stabiliteetin ja retention sekä vähentävät luun resorptiota. Tutkimuksen tarkoituksena oli tutkia mini-implanttikiinnitteisten alaleuan peittoproteesien toimivuutta, potilastyytyväisyyttä ja huoltotoimenpiteiden tarvetta. Tutkimusaineisto koostui seitsemästä tutkittavasta, joilla on mini-implanttikiinnitteiset peittoproteesit alaleuassa. Tutkittavien mini-implanttikiinnitteinen proteettinen hoito on aloitettu vuosien 2010–2012 välillä SEHYK:ssä tai Helsingin yliopiston hammasklinikalla. Tutkittavia pyydettiin arvioimaan proteesiensa toimivuutta ja mukavuutta vastaamalla kyselylomakkeeseen. Lisäksi tutkittiin kliinisesti mini-implanttien, limakalvojen ja proteesien kunto. Mahdollisuuksien mukaan selvitettiin hoitohistoriasta aiemmat huoltotoimenpiteet. Mini-implantteja käytetään lisäämään alaleuan kokoproteesin stabiliteettia vähemmän kuin voisi olettaa verrattuna hampaattomien määrään. Kliinisessä tutkimuksessa havaittiin tavanomaista korjaustarvetta melkein kaikissa proteeseissa. Tärkeintä ylläpitohoidossa on potilaan hyvä suuhygienia ja säännölliset kontrollit. Tulokset vahvistivat hypoteesin, jonka mukaan potilaat ovat tyytyväisiä mini-implantein tuettuun alaleuan kokoproteesiin ja tuntevat olonsa mukavaksi paikoillaan pysyvän proteesin ansiosta.
  • Solén, Taiga (2015)
    When studying hypnosis, it often needs to be known whether the subjects are hypnotizable or not. Hypnotizability can be predicted by suggestibility, which in turn can be estimated with various scales. Different scales yield different estimates of suggestibility. This creates a risk of incorrect comparison of the scores. The comparability of the Harvard Group Scale of Hypnotic Susceptibility (HGSHS:A) and Waterloo-Stanford Group Scale of Hypnotic Susceptibility (WSGC) has not been studied much. Suggestibility is sometimes measured repeatedly with different scales and the order of their administration can affect the scores. This effect has not been studied on the HGSHS:A and the WSGC. This study aims to analyze whether 1) the scores yielded by these scales are affected by the order of their administration, 2) the scores are comparable and 3) corresponding suggestions and types of suggestions are passed equally often. It is expected that the order of administration does affect the scores and even more so for HGSHS:A, 2) the HGSHS:A score is higher than the WSGC and 3) the corresponding suggestions are not passed equally often. 58 subjects were studied, (67% female, 33% male). Both scales were administered to each subject. Half of the subjects were first administered the HGSHS:A and the other half the WSGC. The order of administration did affect the HGSHS:A score but not the WSGC. The hypothesis of the HGSHS:A score being higher was confirmed and the comparability of the scores proved to be less than desirable. There were no significant differences between passing the corresponding suggestions. These results imply that repeated testing might be futile if the right scale is chosen. It is recommended to use the WSGC even for subjects with not former experience of hypnosis. Alternatively, certain suggestions could be used separately to overcome the problems related to the common scales. Specific suggestions are recommended for assessing certain types of suggestibility. Furthermore, a summary of what to take into account when assessing the comparability of different studies is provided.
  • Juuri, Juuso (Helsingin yliopisto, 2015)
    Kainate-type of ionotropic glutamate (KA) receptors are associated with the modulation of neuronal excitability, synaptic transmission, and activity of neuronal networks. They are believed to have an important role in the development of neuronal connections. In this thesis, the role of KA receptors in the early brain development was assessed by conducting in vitro electrophysiological recordings from individual neurons at CA3 region in acute slices of neonatal rodent hippocampi. It was found that activation of separate KA receptor populations promoted action potential firing in both glutamatergic pyramidal neurons and GABAergic interneurons. The receptors in pyramidal neurons displayed a high affinity for agonist kainate, appeared to lack subunit GluK1, and promoted spontaneous firing of pyramidal neurons without depolarizing them. The receptors in interneurons contained subunit GluK1 and their activation suppressed afterhyperpolarizing current of medium duration (ImAHP). Receptors in both neuron types appeared to be activated tonically by ambient glutamate, suggesting that their physiological role may be to act as a modulatory mechanism sensitive to changes in extracellular glutamate concentration. Changes in activity of neurons at CA3 by activation of KA receptors were reflected on the network level. Promotion of pyramidal cell firing by pharmacological activation of high-affinity KA receptors lead to enhanced glutamatergic drive and generation of network bursts in the CA3 region. The ImAHP in interneurons was also suppressed by apamin, a blocker of SK potassium channels that mediate majority of this current, and apamin enhanced generation of network bursts. This suggests that also KA receptor mediated regulation of ImAHP may modulate network activity. It was also found that there was an interaction between KA receptors and ethanol in the modulation of hippocampal network: ethanol decreased the occurrence of the network bursts at postnatal days 1 (P1) and P10, whereas it increased bursting at P5. The network effects of ethanol were partially or completely counteracted by specific pharmacological block of GluK1 subunit-containing KA receptors. The findings disclose that via regulation of activity of individual neurons, KA receptors are capable of robust modulation of network activity in immature hippocampus. Additionally, exogenous agents affecting KA receptors may perturb activity dependent developmental processes that are central for the synaptic development. The results shed light on the mechanisms underlying development of hippocampal connectivity, and may help to understand early pathologies of the brain that have developmental origins.
  • Mogensen, Ditte (Helsingin yliopisto, 2015)
    Forests emit biogenic volatile organic compounds (BVOCs) that, together with e.g. sulfuric acid, can operate as aerosol precursor compounds when oxidised. Aerosol particles affect both air visibility, human health and the Earth s radiative budget, thus making the emission inputs and oxidation mechanisms of VOCs absolutely crucial to understand. This thesis discusses the life cycle of compounds in the atmosphere. Specifically, we studied the representations of emission of BVOCs, the atmosphere s oxidation ability along with the sources and sinks of sulfuric acid. The main tool to achieve this was numerical modelling, often compared to field observations. Additionally, we performed computational chemistry simulations in order to calculate transitions in sulfuric acid. The main findings of this thesis can be summarised into the following: (1) Biological understanding of VOC emission processes needs to be enhanced in order to predict VOC concentrations with a high precision. (2) The unexplained fraction of the total OH reactivity in the boreal forest is larger than the known fraction and known secondary organic oxidation products of primary emitted terpenes cannot explain the missing reactivity. (3) OH is the main oxidation agent of organic compounds in the boreal atmosphere. (4) Criegee Intermediates, produced from unsaturated hydrocarbons, can oxidise SO2 effectively in order to provide as an essential source of sulfuric acid in areas with high VOC concentrations. (5) Two-photon electronic excitation did not turn out to be a significant sink of gaseous sulfuric acid in the stratosphere. This thesis closes a large part of the sulfuric acid concentration gap in VOC rich environments. Further, this thesis raises awareness of the fact that we still do not fully comprehend the mechanisms leading to BVOC emissions nor the organic atmospheric chemistry in the boreal forest. Finally, this work encourage to study alternative BVOC emission sources as well as alternative atmospheric oxidants.
  • Torvi, Paula (2015)
    Tutkielman tarkoituksena on koota yhteen tämänhetkistä tietoa sellaisista syljessä esiintyvistä biomarkkereista, joita on tutkittu siinä toivossa, että ne voisivat olla käyttökelpoisia parodontiitin diagnostiikassa, sekä arvioida löydettyjen markkerien hyödyllisyyttä ja kehittämismahdollisuuksia ja – tarpeita. Tutkielma on muodoltaan kirjallisuuskatsaus, joten sitä laadittaessa perehdyttiin PubMedistä löytyviin artikkeleihin. Artikkelit rajattiin koskemaan viimeisten kahden vuosikymmenen aikana tehtyjä tutkimuksia ja keskityttiin erityisesti 2010-luvulla tehtyihin tutkimuksiin. Kirjallisuuskatsauksessa selvisi, että syljestä voidaan määrittää useita sellaisia biomarkkereita, jotka kertovat jotain parodontiitista. Parodontiitin voidaan havaita nostavan tai laskevan tiettyjen markkereiden pitoisuuksia syljessä, ja osan pitoisuuksista on myös todettu muuttuvan odotetusti hoidon tuloksena. Erityisesti matriksin metalloproteinaasi-8 on osoittautunut lupaavaksi biomarkkerikandidaatiksi parodontiitin sylkidiagnostiikkaan. Tehokas ja kohtuuhintainen parodontiitin sylkitesti olisi käyttökelpoinen potilasjoukkojen seulonnassa, taudin riskin ja etenemisen ennustamisessa, varhaisdiagnostiikassa ja paranemisen seurannassa. Tutkimuksia on aiheesta tehty paljon, mutta osittain tulokset ovat olleet ristiriitaisia. Tarvitaankin lisää erityisesti pitkittäistutkimuksia riittävän suurilla koehenkilöjoukoilla, ennen kuin toivotunlainen parodontiitin sylkitesti saadaan kehitettyä.
  • Saad, Elyana (Helsingin yliopisto, 2015)
    The relationship between mental representations based on external visual percepts (i.e., information held in short-term memory or via mental imagery) and the encoding of visual input remains unsettled. What stimulates this debate is the share of overlapping neural resources between visual short-term memory (VSTM), mental imagery and visual perception in the realm of the early visual cortex (EVC). This overlap raises a number of questions: how do the internal memory and imagery representations affect the perception of incoming visual information? What happens to imagery and VSTM abilities when cognitive resources need to be shared with the encoding of visual input? In short: how do visual memory/imagery and visual perception interact? This work addressed these questions by the use of behavioral paradigms coupled with transcranial magnetic stimulation (TMS) in situations where the encoding of the visual percept (measured via the tilt after effect (TAE) magnitude) happens either simultaneously or subsequently to holding information in VSTM/imagery. Therefore, when VSTM and the encoding of external input occurred concurrently, VSTM maintenance was found to inhibit visual encoding, reflected as a reduction of the TAE. Using TMS, it was shown that this inhibition takes place at the level of EVC. This reduction was found when the VSTM content matched the visual input, and when they were incongruent. However, when the encoding of external input occurred after VSTM maintenance phase had ended, VSTM maintenance was found to facilitate the former when the VSTM content matched the visual input. The subjective strength and the contrast of VSTM and mental imagery content (as reported by participants) affect visual detection of a briefly presented masked target. The reported visual contrast was positively associated with reporting target presence for both VSTM and mental imagery, in other words, inducing a more liberal bias. However, a differential effect was found for the subjective strength of the representations. Whereas the subjective VSTM strength was positively associated with the visual detection of the target, the opposite effect was observed for imagery. Finally, TMS applied at the EVC revealed a partial dissociation in the neural basis of VSTM and mental imagery by inducing delayed responses for the former selectively. Thus, while VSTM and mental imagery share neural resources, their neural mechanisms are partly dissociable at the level of early visual cortex.
  • Kaprio, Tuomas (Helsingin yliopisto, 2015)
    Background and aims Colorectal cancer (CRC) is one of the world s three most common cancers, and its incidence is rising. Novel biomarkers are essential for diagnostic and prognostic tools and to identify patients for targeted and individualized therapy. Covering all human cells, the carbohydrate units of glycoproteins, glycolipids, and proteoglycans are glycans. Carcinoma-related glycan structures are potential cancer biomarkers, since glycosylation evolves during carcinogenesis. Suggested to play a role in carcinogenesis are glycoproteins podocalyxin (PODXL) and regenerating islet-derived gene (REG) 4. PODXL s aberrant expression or allelic variation or both associate in different cancers with poor prognosis and unfavourable clinicopathological characteristics. Up-regulated REG4 expression occurs in inflammatory bowel diseases and also in gastrointestinal cancers. Reports on the association of REG4 expression with CRC prognosis have been mixed, however. Material and Methods Comparison of the N-glycan profiles of 5 rectal adenomas and 18 rectal carcinomas of different stages was by matrix-assisted laser desorption-ionization time-of-flight mass spectrometry. Tumour expression of REG4 and PODXL was evaluated by immunohistochemistry in 840 consecutive CRC patients surgically treated between 1983 and 2001. In addition we evaluated in a subgroup of 220 consecutively surgically treated CRC patients the tumour expression of MUC1, MUC2, MUC5AC, synapthophysin, chromogranin, sialyl Lewis a (sLea), and pauci-mannose. All patients were treated at Helsinki University Hospital (HUH). Results Rectal adenomas and carcinomas can be distinguished from one another based on their N-glycosylation profile. Differences in N-glycosylation existed also between carcinomas of different stages. Based on these results pauci-mannose and sLea were chosen for immunohistochemical analysis: in CRC sLea correlated with poor prognosis, and in advanced CRC, pauci-mannose expression correlated with poor prognosis. PODXL was an independent marker of poor prognosis in CRC. The two antibodies showed similar prognostic profiles, but their staining patterns differed, and they recognized different groups of patients with a poor prognosis. Combination of the two PODXL antibodies identified a group of patients with even worse prognosis. REG4 expression associated with MUC1, MUC2, and MUC5AC expression in CRC and was a marker of favourable prognosis in non-mucinous CRC. Conclusion Mass spectrometry identified several carcinoma-related glycans and a method of transforming these results into immunohistochemistry was demonstrated. PODXL was a marker of poor prognosis in CRC, whereas REG4 expression predicted a favourable prognosis in non-mucinous CRC.
  • Sand, Andrea (Helsingin yliopisto, 2015)
    In the face of the world's increasing demand for energy, and the need to find sustainable and environmentally friendly ways of producing that energy, fusion power offers an attractive possibility. However, the harsh operating conditions of future fusion devices poses a significant challenge for materials development and engineering. Tungsten (W) and tungsten alloys are current candidate materials for both structural and plasma-facing components, due to favourable properties such as good thermal conductivity, high heat strength and stability, and resistance to erosion. However, fusion reactor components will be subjected to high neutron loads, and little is currently known of the effects of radiation on the mechanical properties of this intrinsically brittle metal. The extreme conditions in a future fusion reactor cannot be reproduced in existing experimental facilities, rendering simulation an invaluable tool in understanding the radiation damage processes. Multiscale methods are necessary to span the length and time scales involved, from the picosecond and nanometer scale of displacement cascades giving rise to the primary damage, to the evolution of the radiation induced microstructure over the seconds of typical in-situ ion irradiation experiments, and further to the years of a reactor component s life time. In order to implement a multiscale simulation method, information must be distilled and transferred from the smaller scale to the larger. Molecular dynamics (MD) simulations are ideal for studying the primary damage, but individual cascades vary greatly, and simulating high energy impacts in MD requires immense computer capacity. It is therefore not possible to simulate directly the whole variety of cascade outcomes. General laws deduced from the MD data can, however, be used to statistically generate varying cascades in the thousands. In this thesis we use MD simulations to study the primary damage in metals, with focus on tungsten. We identify aspects of the simulation methodology which affect the results, and validate our methods by direct comparison to experiments. Detailed analysis of the primary damage from high-energy cascades shows the formation of novel defects, confirming recent experimental observations. We also show that defect cluster sizes follow a general scaling law, which can be used to statistically generate cascade debris as input for microstructural evolution models, circumventing the need to directly simulate thousands of cascades.
  • Hämäläinen, Saara (Helsingin yliopisto, 2015)
    Our thesis has three individual papers and an introduction. It contributes to dynamic price and search theory. The first paper deals with the classic problem of trading under asymmetric information. The other two analyze retailing strategies that help lock in buyers by creating in-store frictions. In the first paper, we investigate welfare and equilibrium trading in a decentralized search market with asymmetric information and bilateral communication opportunities. Sellers and buyers meet randomly and pairwise and view a shared signal of the seller's quality. In the following signaling game, the sellers can either rely on this costless signal (pool) or costly signaling (separate). We observe that, although the average market quality is high, additional information is not generally welfare improving. All equilibria are inefficient. Contrary to the usual tradeoff between price and liquidity, we find that the signals can help sustaining stationary Markovian equilibria where higher quality is traded faster. In the second paper, we construct a novel search model that features in-store frictions and equilibrium price dispersion both within and across stores. The frictions originate from the gradual arrival of price information within stores and the existence of deadlines for buyers. We show that sellers have an incentive carry several similar items and generate price variation among these items to amplify the existing search frictions and create barriers to switching in an environment where none exist initially. It also helps them to discriminate better between buyers, who end with diverse degrees of price information. As the number of items in stock expands, sellers can extract more profits. In our third paper, we develop a price search model that features endogenous frictions in a duopolistic environment. These frictions originate from the gradual arrival or price information within stores and the existence of deadlines for buyers. We show that both sellers have a strategic incentive to generate frictions. There exists exactly two equilibria with a unique asymmetric pattern: a prominent seller, whose expected price is higher but the in-store frictions lower, and a non-prominent seller. The buyers are divided exactly equally into informed and uninformed consumers, and into those who fail to find anything. Under the Poisson process, this surplus loss is about 6 %.
  • Guan, Yucong (Helsingin yliopisto, 2014)
    The ongoing industrial globalization and high dependence on natural resources have stimulated forest companies to balance diverse and conflicting stakeholder demands and to disclose sustainability initiatives through corporate disclosures (Li and Toppinen, 2011). The identification of business impacts and risks associated with biodiversity and ecosystem services in the Millennium Ecosystem Assessment (2005) has triggered corporations to report their initiatives and performance on such issues, especially corporations in the environmentally sensitive sectors. In order to investigate the current state of reporting on biodiversity and ecosystem services in the forest sector, a content analysis was implemented based on the Global Reporting Initiatives (the G3.1 version) environmental performance indicators for analyzing sustainability-related reports of thirteen globally operating forest companies in this study. The focus of the content analysis was on initiatives and environmental performance regarding five key threats to biodiversity and ecosystem services: the threat of habitat loss and degradation, the threat of over exploitation and unsustainable use, the threat of climate change, the threat of pollution and nutrient load and the threat of invasive alien species. The results indicate that reporting variations exist in terms of geographical locations and content-specific characteristics. In general, environmental subcategories of products and services, emission/effluents and biodiversity are the most reported. Regarding the five key threats to biodiversity and ecosystem services, the threat of over exploitation and unattainable use is the most comprehensively reported while the threat of invasive alien species is the least reported. Based on the GRI sector supplements in other environmentally friendly sectors, industrial features of the forest sector and inter-linking issues detected between/among three sustainability dimensions, tentative suggestions and indicators are proposed for the forest sector supplement from biodiversity and ecosystem services perspective. Biodiversity and ecosystem services will probably be a subject of mandatory reporting with the assistance of a transparent and rigid reporting system. Inter-linking issues between/among sustainability dimensions and stakeholder involvement in environmental issues will be cornerstones in integrated reporting in the future.
  • Helmiö, Päivi (Helsingin yliopisto, 2015)
    TOWARDS BETTER PATIENT SAFETY: The WHO Surgical Checklist in Otorhinolaryngology More than one-half of adverse events in health care are related to surgery. Surgical patient injuries account for about 80% of patient injuries in otorhinolaryngology (ORL). The World Health Organisation (WHO) has developed a Surgical Safety Checklist to prevent errors in the operating theatre. Its use has been shown to reduce complications and mortality. The aims of the present study were to identify errors that may underlie those patient injuries that occur in operative ORL, to assess the effects of the WHO checklist on working processes in the operating theatre, including compliance, and to evaluate how it would fit into the specialty. Data of the patient injuries that were sustained during treatment by the ORL specialty between the years 2001 and 2011 were obtained from a search of the Finnish Patient Insurance Centre registry. The causes of the injuries were analysed, and whether the WHO checklist could have prevented the error was evaluated. The checklist was implemented in four Finnish hospitals as a pilot in 2009. A prospective before-versus-after-intervention study was conducted with a questionnaire for OT personnel in these four hospitals to evaluate the checklist. The checklist was subsequently implemented for regular use in the operative unit of the Department of Otorhinolaryngology of Helsinki University Central Hospital. After one-year of use, compliance and user attitudes were analysed by using data obtained from the operations database and a survey of operative ORL personnel. In the 10-year study period, 188 patient injuries were associated with operative ORL. A total of 142 (75.5%) of these injuries occurred due to errors that were made in the operating theatre, and in 125 cases (66.5%) a manual error in performing the surgery was the primary cause of the injury. Six injuries (3.2%) were caused by wrong site surgery. An error had some degree correspondence with a WHO checklist item for 18 injuries (9.6%) and it was determined that 9 of these injuries (4.8%) could have been prevented had the checklist been correctly used. The implementation of the checklist enhanced the communication between the surgical team members, improved verification of the patient s identity and of the correct operation site. Checklist compliance was 62.3% during first year of use. It was considered easy to use and the Safety Attitude Scores of the personnel were found to be on a high level. All check items on the list were considered important for ORL. However, a more compact checklist for outpatient surgery was requested. Patient injuries in ORL were strongly related to surgery. The WHO Surgical Safety Checklist seems to be a beneficial tool for preventing errors ORL and is highly relevant for the specialty.
  • Turunen, Harri (Helsingin yliopisto, 2015)
    I study the importance of variation in the higher moments of macroeconomic and financial quantities. The first essay considers the effects of uncertainty on the fiscal multiplier when the economy has hit the zero lower bound (ZLB) on the nominal rate in a relatively standard New Keynesian Dynamic Stochastic General Equilibrium (DSGE) model. As the ZLB is a very strong form of nonlinearity, the model is solved using a numerical method. Uncertainty in government spending and productivity are modeled as stochastic volatility. Confirming previous research (e.g. Christiano, Eichenbaum and Rebelo, 2011), the multiplier is found to be higher when at the bound, and the effects of volatility shocks are found to be noticeable (e.g. Basu and Bundick, 2015). Uncertainty is found to have an impact on the multiplier: when future spending is uncertain, the multiplier is high, but when future productivity is uncertain, the multiplier is low. The second essay studies whether or not DSGEs are able to generate simulated realizations with realistic third and fourth moments. Many time series in macroeconomics and finance exhibit either excess kurtosis or skewness or both. However, as was shown by Ascari et al (2013), standard DSGEs such as the neoclassical growth model or the model of Smets and Wouters (2007) are unable to produce realizations with reasonable moments, regardless of shock distribution or the order of the Taylor approximation applied. My results however indicate that this is mostly due to lack of nonlinearity in the models, since especially a model with a very strong form of nonlinearity, such as the ZLB, is able to generate non-Gaussian realizations. The third essay considers the pricing of macroeconomic risk. The theory of Merton (1973) implies that there can be other sources of priced risk than the risk associated with the return on the market portfolio and that an appropriate measure for sensitivity of a stock to this risk is the covariance of the return of that stock with the source of that risk. I apply the multivariate volatility model of Engle (2002) to estimate time-varying covariances of US stock portfolios with a variety of US macro time series. The finding is that inflation and unemployment are priced in the market and earn a negative premium, while the growth rate of industrial production and the Case-Shiller house price index are not priced.