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  • Silvast, Antti (Helsingin yliopisto, 2013)
    During the past ten years, a number of social scientists have emphasized the importance of material infrastructures like electricity supply as a research topic for the social sciences. The developing of such new perspectives concerning infrastructures also includes uncertainties and risks. This research analyzes the management of uncertainties in the Finnish electricity infrastructure by posing the following research question: how are electricity interruptions, or blackouts, anticipated in Finland and how are these interruptions managed as risks? The main research methodology of the work is multi-sited field work. The empirical materials include interviews with experts and lay people (33 interviews); participant observation in two electricity control rooms; an electricity consumer survey (115 respondents); and also a number of infrastructure and security policy documents and observations from electricity security seminars. The materials were primarily gathered between 2004 and 2008. Social science research often links risks with major current social changes or socio-cultural risk perceptions. In recent international social science discussions, however, a new research topic has emerged those styles of reasoning and techniques of governance that are deployed to manage risk as a practical matter. My study explores these themes empirically by focusing on the specific habitual practices of risk management in the Finnish electricity infrastructure. The work develops various also semi-ethnographic inquiries into infrastructure risk techniques like monitor screening of real-time risks in electricity control rooms; the management of risks in a liberalized electricity market; the emergence of Finnish reasoning about blackouts from a specific historical background; and the ways in which electricity consumers respond to blackouts in their homes. In addition, the work reflects upon the position of a risk researcher in those situations when the research subjects do not define their management of uncertainties by the concept of risk. The work argues based on recent studies and its results that risk discourse in national and military planning offers a substantial resource to consider infrastructures and their contemporary issues. It also considers the idea, prominent in recent studies concerning insurance in particular, that risk management is a way of combining both public and market logics of provision. Drawing on semi-ethnographic data, the author also discusses the compression of timescales in liberalized infrastructure provision and elaborates the metaphor of screening to consider how market devices like computer monitors affect risk management in a large distributed energy market.
  • Lehtonen, Esko (Helsingin yliopisto, 2014)
    In the visual control of locomotion, gaze is used to sample information in an anticipatory manner. In car driving, this anticipation functions at both a short and long time distance. At the short time distance, gaze leads the locomotion with a small (1‒3 s) time headway. Many steering models have explained this behavior by interpreting that drivers track a steering point on the road to obtain visual information which is directly translated to steering actions. This gaze behaviour can be called guiding fixations, because the gaze is providing information for the online control of the steering. At the long time distance, gaze serves trajectory planning by picking up information from the road further ahead. In curves, a part of the road can be visible in highly eccentric positions relative to the typical guiding fixations direction. In these situations, the information needs of the trajectory planning can result in eccentric look-ahead fixations toward the curve. The role of these fixations in the visual control of locomotion is not well understood. In this thesis, I have developed algorithmical methods for the identification of look-ahead fixations from eye movement data collected with an instrumented vehicle on real roads. In a series of three experiments, gaze behavior in curves was studied. The effects of driving experience and cognitive load were also investigated. In general, fixation distributions do not suggest a clear division between guiding and look-ahead fixations. However, a clear tail of eccentric fixations is present in the distributions, which can be operationally defined as look-ahead fixations in curves. Look-ahead fixations target the whole visible road, but locations with a smaller eccentricity relative to the guiding fixations were more commonly fixated than those with a high eccentricity. Experienced drivers allocated more time to look-ahead fixations compared to novices. Cognitive load may negatively affect trajectory planning by interfering with look-ahead fixations. Based on the results, the role of trajectory planning in the control of steering is discussed. The results are consistent with a hierarchical model of driving behaviour, where trajectory planning supplies the intended path for the level of the online control of steering.
  • Mälkiä, Reijo (Helsingfors universitet, )
    Länsimaisen rakennustaiteen perusta on antiikin Kreikan rakennustaiteessa, erityisesti sen temppelirakentamisessa. Kreikkalaisen temppelin kauneuden avainta on etsitty vuosisatoja alkaen roomalaisaikaisesta Vitruviuksesta. Löytyykö se luonnosta, luonnonmuotojen jäljittelystä? Löytyykö analogioita kieleen tai musiikkiin? Vai perustuuko kaikki kauneus matemaattisiin sääntöihin? Pohjana tarkastelulleni on Peloponnesoksen kupeessa sijaitsevasta Poroksen temppelistä 500-luvulta eKr. saatu tutkimustieto ja temppelialueen arkeologisiin kaivauksiin tutustuminen. Sen laajennan koskemaan doorilaista ja yleensäkin kreikkalaista temppeliä. Tutkimuskysymykseni on, mitkä tekijät johtivat antiikin kreikkalaisten temppelirakennuksen kehittymiseen sellaiseksi kuin sen tunnemme. Ja hypoteesini on, että temppelityypin synnylle keskeistä ovat vallinneet yhteiskunnalliset tuotanto- ja valtasuhteet, kreikkalaisen filosofian ajatussuunnat sekä muun kreikkalaisen kulttuurin ja taide-elämän antamat vaikutteet. Toissijaisena olettamuksena minulla on ollut, että kreikkalaisen temppelin lähtökohta, megaron, on pääosin saatu pronssikaudella Levantista, palestiinalais-syyrialaisesta temppelistä. Käyttämälläni aineistolla pystyy mielestäni perustelemaan hypoteesit. Viittaan muun muassa siteeraamiini tulkintoihin Platonin, Aristoteleen ja muiden filosofien teksteistä. Lisäksi temppelirakentaminen on läheisesti liittynyt urbanisoitumiseen, erityisesti ruutukaavapoliksen syntyyn. Kreikkalainen arkkitehtuuri oli osaltaan luomassa kaupunkirakennetta ja –tiloja, jotka edistivät ihmisten kohtaamista ja kokoontumista sekä kokemusta tasa-arvoisuudesta. Tämä osaltaan edisti demokraattisen hallintomallin kehittymistä. Olen pyrkinyt myös visuaalisesti näyttämään kreikkalaisen temppelin ennen kaikkea näkemisen asiana sekä temppelialueen istuttamisen kaupunkirakentamiseen. Myös yhteys muihin taiteisiin vaikuttaa selvältä, olihan temppeli kokonaistaideteos, jonka korkokuvat ja maalaukset saattoivat kiinnostaa aikalaisia enemmän kuin itse rakennus. Arkeologisten löytöjen perusteella on osoitettavissa, että niin doorilaisen kuin joonialaisen järjestelmän rakentuminen jo yhdeksännellä vuosisadalla on hahmotettavissa attikalaisessa ja itäkreikkalaisessa maljakkomaalauksessa. Kreikkalaisen temppelin juurien johtaminen Palestiinaan vaatii lisää tutkimustietoa. Riittääkö siihen megaron-sanan heprealainen kieliasu, vastaavanlaisen sakraalirakennustyypin olemassaolo tai Palestiinasta peräisin olevien esineiden löytyminen kreikkalaistemppeleiden kaivauksista kuten Porokseltakin? Mutta jos tulkintani on oikea, se avaa aivan uusia näkökulmia kulttuurimme alkulähteistä.
  • Ervamaa, Suvi (2003)
    Tutkimuksessa vertaillaan vuosina 1968-1973 Helsingissä toiminutta TRICONT-järjestöä ja nykyistä Suomen Attacia. Näiden liikkeiden voidaan katsoa ilmentävän viime vuosikymmenten aikana kehittynyttä uutta tietoisuutta Suomesta osana kansainvälisen taloudellis-poliittisen muutoksen prosessia, jota nykyisin kutsutaan globalisaatioksi. TRICONTin tarkastelu luo Attacille historiallista taustaa. Empiirisen analyysin menetelmä ja viitekehys perustuvat Ron Eyermanin ja Andrew Jamisonin kehittelemään kognitiiviseen näkökulmaan, jossa yhteiskunnallisia liikkeitä tarkastellaan toisaalta merkitysten, tiedon ja identiteettien tuottajina, toisaalta tietyssä historiallisessa kontekstissa operoivina strategisina toimijoina. Tutkimus esittelee TRICONTin ja Attacin maailmankuvat, tavoitteet, toimintatavat ja poliittiset strategiat. Tarkoituksena on hahmottaa globaalisti orientoituneen aktivismin muutosta Suomessa. Yhteiskunnallisten liikkeiden toiminta ja niiden esille tuomat kysymykset ja vaatimukset ovat ymmärrettävissä vain suhteessa aikaan ja paikkaan. Tästä syystä tutkimuksessa kuvataan myös niitä historiallisia, taloudellisia ja poliittisia konteksteja, joissa TRICONT ja Attac operoivat. Neuvostoliiton ja sen satelliittivaltioiden yhteiskuntajärjestelmien romahdus sekä siitä seurannut marxismiin pohjautuvien yhteiskuntateorioiden inflaatio on vaikuttanut voimakkaasti siihen, millaisia maailmankuvallisia elementtejä, tavoitteita ja strategioita nykyinen globalisaatiokriittinen liike katsoo mielekkääksi kehittää. Sosialismin projekti on menettänyt legitimiteettinsä poliittisena vaihtoehtona, eivätkä liberaalin demokratian ja markkinatalouden järjestelmät ainakaan toistaiseksi ole saaneet rinnalleen varteenotettavia kilpailijoita. Tästä syystä Suomen Attac, toisin kuin TRICONT 1960-luvulla, suhtautuu valtioon yhteistyökumppanina eikä vastusta markkinatalousjärjestelmää sinänsä. Attacin esiin tuomat poliittiset tavoitteet liittyvät pikemminkin markkinatalouden ja poliittisen hallinnan välisten voimasuhteiden säätelyyn. Arvioin empiirisen osan tulosten valossa Jürgen Habermasin esittämää ja Alberto Meluccin edelleen kehittelemää liiketutkimusmallia, jonka mukaan yhteiskunnalliset liikkeet olisi tulkittava reaktioksi prosessiin, jossa talouden ja valtiollisen hallinnan sfäärit kolonisoivat elämismaailmaa. Tutkimus osoittaa, että Habermasin ja Meluccin kehittelemä malli sisältää seuraavat puutteet: 1) Malli ei huomioi viime vuosikymmeninä kiihtynyttä prosessia, jossa markkinat kolonisoivat poliittista hallintaa. 2) Malli näyttää vanhentuneen siltä osin, että yhteiskunnalliset liikkeet eivät enää välttämättä koe valtiota vastustajakseen, vaan pyrkivät markkinoiden hallintaan nimenomaan valtioiden sisäisen ja välisen poliittisen regulaation ja sopimusten kautta. 3) Malli rajoittuu kansallisvaltion tasoiseen kuvaukseen, vaikka yhteiskunnalliset liikkeet operoivat kasvavassa määrin globaalissa kontekstissa Tärkeimmät tutkimuksessa käytetyt lähdeteokset ovat Eyerman, Ron & Jamison, Andrew (1991): Social Movements. A Cognitive Approach sekä Jamison, Andrew, Ron Eyerman, Jaqueline Cramer & Jeppe Læssoe (1990): The Making of the New Environmental Consciousness. A Comparative Study of the Environmental Movements in Sweden, Denmark and Netherlands.
  • Kreutzman, Anna (Helsingin yliopisto, 2012)
    Tyrosine kinase inhibitors (TKIs), such as imatinib (Glivec®) and dasatinib (Sprycel®), have dramatically improved the outcome of chronic myeloid leukemia (CML) patients. Besides inhibiting the actual on-target BCR-ABL1 kinase in leukemic cells, TKIs also inhibit several off-target kinases, which may affect healthy cells. Dasatinib has a particularly wide kinase-inhibition profile and inhibits kinases important in immune effector cells, such as SRC-kinases. Opposite to immunosuppressive in vitro effects, dasatinib induces an oligoclonal expansion of large granular lymphocytes (LGLs) in the blood in vivo, which has been associated with improved therapy responses. The purpose of this PhD thesis was to uncover the cellular and molecular mechanisms of dasatinib-related LGL lymphocytosis. Unlike healthy controls, clonal lymphocytes were detected in the majority of CML patients at diagnosis. During dasatinib therapy these clones expanded, eventually leading to absolute lymphocytosis. Hypothetically, the lymphocyte clones detected at diagnosis are unresponsive (anergic) anti-leukemic clones, which recover, reactivate and expand during dasatinib therapy. In concord, the expanded CD8+ T cells and NK cells had a late differentiated phenotype of long-lived T-cells. The long-term dasatinib treatment also differentiated CD4+ T cells into cytotoxic LGLs. These unique CD4-LGLs secreted increased amounts of IFN-gamma indicating a sensitized role in eliminating leukemic cells. Dasatinib therapy also enhanced the cytotoxicity of NK cells. Immunomodulatory effects of IFN-α treatment in CML patients were also studied. Previous work have shown that a small proportion of IFN-α treated patients can permanently discontinue therapy without relapse. This curative property of IFN-α could be caused by an immune mediated mechanism and as a proof of this, we noticed that patients who had responded very well to treatment, had an increased number of CD8+ T cells and unique clonal γ/δ T cells. Intriguingly, patients who were able to stop the treatment also had significantly higher numbers of NK cells. Taken together, the results in this PhD project provide a proof of a unique, previously unrecognized dual mode of action of TKI-treatment: direct cytotoxic effects are accompanied with the activation of immune system which is potentially relevant for the long-term control of CML. These findings can be utilized in developing novel immunotargeting therapies of leukemia and other cancers.
  • Rantala, Merja (Helsingin yliopisto, 2009)
    Aims: This thesis investigated the prevalence of and trends in antimicrobial resistance in pneumococci in Finland, determined the genetic basis of macrolide resistance and evaluated the level of telithromycin nonsusceptibility prior to its widespread usage. In addition, the clonality of telithromycin-resistant and penicillin-resistant isolates was examined. Results: Of the 1007 pneumococci collected in 2002, 21.5%, 12.1%, and 14.4% were non-susceptible to erythromycin, penicillin and tetracycline, respectively. Multiresistance was detected in 10.5% of the isolates. Only 0.1% of the isolates were non-susceptible to ceftriaxone (non-meningitis breakpoint) and <1.5% to fluoroquinolones. Two isolates were nonsusceptible to linezolide. Among invasive pneumococci (n=3571) collected in 2002-2006, erythromycin resistance increased from 16% (2002) to 28% (2006) (Poisson regression, p < 0.0001), penicillin non-susceptibility from 8% to 16% (< 0.0001) and penicillin resistance from 0.8% to 3.7% (p = 0.03). Tetracycline resistance remained stable (~10%), as did the proportion of multiresistant isolates (~5%). Levofloxacin and ceftriaxone resistance was rare. In both sets of collections of pneumococci, the highest prevalence of erythromycin resistance was among isolates derived from 0- to 2-year-old children: in 2006, 45.8% of isolates were resistant to erythromycin in this age group. In 2002, disk diffusion testing revealed 26/1007 (2.6%) pneumococcal isolates that produced one to several clearly visible colonies inside the growth inhibition zone, indicating heterogeneous resistance to telithromycin. This type of telithromycin resistance has not been previously described. All such isolates were erm(B) positive, but the exact underlying mechanism of telithromycin resistance remained unresolved. Telithromycin resistant isolates had seven distinct sequence types, of which ST193 was the most frequent (n = 19). ST193 isolates were all 19A serotype variants of the PMEN clone Greece21-30. Among penicillin resistant isolates in 2002-2006, a total of 25 sequence types were found that distributed into ten clonal lineages. The most common clonal complex was CC156, accounting for 61% of all penicillin resistant isolates. The majority of the penicillin-resistant pneumococci were representatives of single to triple locus variants of the following PMEN clones: Spain9V ST156, Taiwan19F ST236, Spain23F ST81, and England14 ST9. In 2002, the most frequent macrolide resistance gene was the mef gene (49%), followed by erm(B) (41%). A double mechanism [mef(E)+erm(B)] was detected in 5 (2.3%) isolates. Of the mef genes, 89% had the mef(E) subclass and 11% had mef(A). Mutation was detected in 16 isolates, of which 14 isolates (6.4%) had no other known resistance factor. In 2002-2006 the macrolide gene distribution was the following: 56% of the macrolide resistant isolates had mef gene and 31% had erm(B). Only two isolates had both mef(E) and erm(B). mef(E) was the most common mef subtype (72%). Conclusions: The main observation of this thesis was the presence ofheterogeneous telithromycin resistance among pneumococci carrying erm(B). Such isolates harbour a minor population of bacterial cells capable of expressing high level telithromycin resistance in vitro, which may be clinically significant. Because dilution methods do not favour the detection of this resistance type, the disk diffusion susceptibility testing of erm(B)-positive pneumococci is recommended. Due to the high prevalence of resistance, macrolides cannot be recommended as the first line drugs for the treatment of pneumococcal infections. Apart from macrolide resistance, the proportion of penicillin non-susceptible isolates is rising.
  • Rummukainen, Maija-Liisa (Helsingin yliopisto, 2013)
    Background and aims. The rapidly growing ageing population results in a demand for new types of housing that may face the same challenges as nursing homes (NHs) do today. Elderly persons are at particular risk for healthcare-associated infections, since few long-term care facilities (LTCFs) have in-house expertise in infection control or in infectious diseases. This may lead to inappropriate prescription of antimicrobials and promote development of multidrug-resistant bacteria. The movement of residents between LTCFs and acute-care hospitals facilitates the spread of resistant bacteria. The aim of the present study was to determine the use of antimicrobials and prevalence of infections in LTCFs in Finland. An additional aim was to evaluate the feasibility of different methods in assessing antibiotic use and prevalence of infections in LTCFs. Methods. A team comprising an infectious disease consultant, an infection control nurse, and a geriatrician visited all 123 LTCFs for elderly persons in the Central Finland Healthcare District during 2004 2005. The site visits consisted of a structured interview concerning patients, ongoing systemic antimicrobial use, diagnostic practices for urinary tract infection (UTI), and monthly amount in liters of alcohol-based hand rubs used and in patient-days. Following the visits, regional guidelines for prudent use of antimicrobials in LTCFs were published and the use of antimicrobials was followed up by an annual questionnaire during 2006-2008. All residents present in nine voluntary NHs for ≥ 24 hours (n = 5,791) and receiving systemic antimicrobials on the day of the survey were included in the study. Data on antibiotics and their indications (prophylaxis or treatment, type of infection) were collected in April and November 2009 and May-September 2010. All residents for whom a Minimum Data Set (MDS) form (n = 12,784) was completed in 753 LTCFs using a Resident Assessment Instrument (RAI) in April and September 2011 were included. Results. The proportions of patients receiving antimicrobials in surveys varied between 10% and 19%. Most of the antimicrobials were used for UTI prophylaxis (42-69%) and treatment (13-25%). The proportion of patients on UTI prophylaxis decreased in the Central Finland Healthcare District from 13% to 6% and in eight NHs from 12% to 6%. The most common antimicrobial used was methenamine (36-44%), followed by trimetoprim (14-31%), cephalexin (6-9%), and pivmecillinam (6-11%). In Central Finland Healthcare District LTCFs, the total amount of alcohol-based hand rub used increased by 70%, from the mean (SD) of 7.3 (5.1) L/1000 patient-days on the baseline visit in 2005 to 12.4 (14.9) L in 2008. In LTCFs using RAI, the risk factors for antimicrobial prescription included female sex, age < 85 years, urinary catheter, urinary incontinence, confusion, restriction to bed, pressure ulcers, diarrhea, and hospital stay during the previous 90 days. Conclusions. Antimicrobial use was common in Finnish LTCFs and most were used for UTI prophylaxis and treatment. The decrease in antimicrobial usage during the surveys suggests that LTCFs may benefit from antimicrobial stewardship interventions focused on UTI. The multidisciplinary team succeeded in promoting hand hygiene in LTCFs, which was sustained over the 3-year follow-up. RAI with MDS data also constitutes a feasible tool for collecting data on antibiotic use and infections in LTCFs.
  • Pessi, Risto (1994)
  • Järvinen, Kristiina (Helsingin yliopisto, 2001)
  • Kataja-Tuomola, Merja (Helsingin yliopisto, 2011)
    The incidence of type 2 diabetes has increased rapidly worldwide. Obesity is one of the most important modifiable risk factors of type 2 diabetes: weight gain increases and weight loss decreases the risk. However, the effects of weight fluctuation are unclear. Reactive oxygen species are presumably part of the complicated mechanism for the development of insulin resistance and beta-cell destruction in the pancreas. The association of antioxidants with the risk of incident type 2 diabetes has been studied in longitudinal prospective human studies, but so far there is no clear conclusion about protective effect of dietary or of supplementary antioxidants on diabetes risk. The present study examined 1) weight change and fluctuation as risk factors for incident type 2 diabetes; 2) the association of baseline serum alpha-tocopherol or beta-carotene concentration and dietary intake of antioxidants with the risk of type 2 diabetes; 3) the effect of supplementation with alpha-tocopherol or beta-carotene on the risk of incident type 2 diabetes; and on macrovascular complications and mortality among type 2 diabetics. This investigation was part of the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study, a randomized, double-blind, placebo-controlled prevention trial, which has undertaken to examine the effect of alpha-tocopherol and beta-carotene supplementation on the development of lung cancer, other cancers, and cardiovascular diseases in male smokers aged 50-69 years at baseline. Participants were assigned to receive either 50 mg alpha-tocopherol, 20mg beta-carotene, both, or placebo daily in a 2 x 2 factorial design experiment during 1985-1993. Cases of incident diabetes were identified through a nationwide register of drug reimbursements of the Social Insurance Institution. At baseline 1700 men had a history of diabetes. Among those (n = 27 379) with no diabetes at baseline 305 new cases of type 2 diabetes were recognized during the intervention period and 705 during the whole follow-up to 12.5 years. Weight gain and weight fluctuation measured over a three year period were independent risk factors for subsequent incident type 2 diabetes. Relative risk (RR) was 1.77 (95% confidence interval [CI] 1.44-2.17) for weight gain of at least 4 kg compared to those with a weight change of less than 4 kg. The RR in the highest weight fluctuation quintile compared to the lowest was 1.64 (95% CI 1.24-2.17). Dietary tocopherols and tocotrienols as well as dietary carotenoids, flavonols, flavones and vitamin C were not associated with the risk of type 2 diabetes. Baseline serum alpha-tocopherol and beta-carotene concentrations were not associated with the risk of incident diabetes. Neither alpha-tocopherol nor beta-carotene supplementation affected the risk of diabetes. The relative risks for participants who received alpha-tocopherol compared with nonrecipients and for participants who received beta-carotene compared with nonrecipients were 0.92 (95% CI 0.79-1.07) and 0.99 (95% CI 0.85-1.15), respectively. Furthermore, alpha-tocopherol or beta-carotene supplementation did not affect the risk of macrovascular complications or mortality of diabetic subjects during the 19 years follow-up time. In conclusion, in this study of older middle-aged male smokers, weight gain and weight fluctuation were independent risk factors for type 2 diabetes. Intake of antioxidants or serum alpha-tocopherol or beta-carotene concentrations were not associated with the risk of type 2 diabetes. Supplementation with of alpha-tocopherol or beta-carotene did not prevent type 2 diabetes. Neither did they prevent macrovascular complications, or mortality among diabetic subjects.
  • Parikka, Kirsti (Helsingin yliopisto, 2007)
    The first synthesis of long chain 5-n-alkylresorcinols (C15-C25) in whole grains and whole grain products by a novel modification of Wittig reaction is described. 5-n-Alkylresorcinols are phenolic lipids that have various effects on biological systems, such as antioxidant activity and interaction with biological membranes. These compounds are considered as biomarkers of whole grain intake, which is connected with reduced risk of cardiovascular diseases and certain cancers. Novel hapten derivatives of 5-n-alkylresorcinols, potential compounds for immunoanalytical techniques, are prepared by the same procedure utilizing microwave catalysed aqueous Wittig reaction as the key step. The synthesised analogues are required by various analytical, metabolism and bioactivity investigations. Four alternative strategies for producing deuterium polylabelled 5-n-alkylresorcinols are explored. Ring-labelled D3-alkylresorcinols were synthesized by acidic H/D exchange. Side chain -labelled D4-derivative was prepared by a total synthesis approach utilizing D2 deuterogenation of a D2-alkene derivative, and deuterogenation of alkynes was investigated in another total synthesis approach. An -D3-labelled alkylresorcinol is isotopically pure and completely stable under all relevant conditions encountered during analytical work. The labelling of another phenolic component of whole grains was explored. The preparation of D3-ferulic acid and related compounds by way of selective methylation of the precursors is described. The deuterated compounds are useful as standards in the quantification of these natural products in various substances, such as food and human fluids. The pure 5-n-alkylresorcinol analogues prepared were used in in vitro experiments on alkylresorcinol antioxidant activity and antigenotoxicity. The in vitro experiments show that alkylresorcinols act as antioxidants, especially when incorporated into biological systems, but possess lower activity in chemical tests (FRAP and DPPH assay). Whole grain alkylresorcinols are shown for the first time to have a protective effect against copper induced oxidation of LDL, and H2O2 or genotoxic faecal water induced damage on HT29 cells.
  • Lindén, Eveliina (Helsingin yliopisto, 2006)
    Predation is an important source of mortality for most aquatic animals. Thus, the ability to avoid being eaten brings substantial fitness benefits to individuals. Predator detection abilities and antipredator behaviour were examined in various planktivores, i.e. the littoral mysids Neomysis integer and Praunus flexuosus, three-spined stickleback Gasterosteus aculeatus larvae, pelagic mysids Mysis mixta and M. relicta, and the predatory cladoceran Cercopagis pengoi, with cues from their respective predators European perch Perca fluviatilis and Baltic herring Clupea harengus membras. The use of different aquatic macrophytes as predation refuges by the littoral planktivores was also examined. All pelagic planktivores and stickleback larvae were able to detect the presence of their predator by chemical cues alone. The littoral mysids N. integer and P. flexuosus responded only when chemical and visual predator cues were combined. The responses of stickleback larvae were stronger to the combined cues than the chemical cue alone. A common antipredator behaviour in all of the planktivores studied was decreased ingestion rate in response to predator cues. N. integer and stickleback larvae also decreased their swimming activity. Pelagic mysids and C. pengoi altered their prey selectivity patterns in response to predator cues. The effects of predator cues on the swarming behaviour of N. integer were examined. Swarming brings clear antipredator advantages to N. integer, since when they feed in a swarm, they do not significantly decrease their feeding rate. However, the swarming behaviour of N. integer was not affected by predation risk, but was instead a fixed strategy. Despite the presence or absence of predator cues, N. integer individuals attempted to associate with a swarm and preferred larger to smaller swarms. In studies with aquatic macrophytes, stickleback larvae and P. flexuosus utilized vegetation as a predation refuge, spending more time within vegetation when under predation threat. The two macroalgal species studied, bladderwrack Fucus vesiculosus and stonewort Chara tomentosa, were preferred by P. flexuosus, whereas Eurasian watermilfoil Myriophyllum spicatum was strongly avoided by N. integer and stickleback larvae. In fact, when in dense patches in aquaria, M. spicatum caused acute and high mortality (> 70%) in littoral mysids, but not in sticklebacks, whereas C. tomentosa and northern watermilfoil M. sibiricum did not. In contrast, only 2-4% mortality in N. integer was observed with intact and broken stems of M. spicatum in field experiments. The distribution of littoral mysids in different vegetations, however, suggests that N. integer avoids areas vegetated by M. spicatum.
  • Tynjälä, Pirjo (Helsingin yliopisto, 2008)
    Juvenile idiopathic arthritis (JIA) is a heterogeneous group of childhood chronic arthritides, associated with chronic uveitis in 20% of cases. For JIA patients responding inadequately to conventional disease-modifying anti-rheumatic drugs (DMARDs), biologic therapies, anti-tumor necrosis factor (anti-TNF) agents are available. In this retrospective multicenter study, 258 JIA-patients refractory to DMARDs and receiving biologic agents during 1999-2007 were included. Prior to initiation of anti-TNFs, growth velocity of 71 patients was delayed in 75% and normal in 25%. Those with delayed growth demonstrated a significant increase in growth velocity after initiation of anti-TNFs. Increase in growth rate was unrelated to pubertal growth spurt. No change was observed in skeletal maturation before and after anti-TNFs. The strongest predictor of change in growth velocity was growth rate prior to anti-TNFs. Change in inflammatory activity remained a significant predictor even after decrease in glucocorticoids was taken into account. In JIA-associated uveitis, impact of two first-line biologic agents, etanercept and infliximab, and second-line or third-line anti-TNF agent, adalimumab, was evaluated. In 108 refractory JIA patients receiving etanercept or infliximab, uveitis occurred in 45 (42%). Uveitis improved in 14 (31%), no change was observed in 14 (31%), and in 17 (38%) uveitis worsened. Uveitis improved more frequently (p=0.047) and frequency of annual uveitis flares was lower (p=0.015) in those on infliximab than in those on etanercept. In 20 patients taking adalimumab, 19 (95%) had previously failed etanercept and/or infliximab. In 7 patients (35%) uveitis improved, in one (5%) worsened, and in 12 (60%) no change occurred. Those with improved uveitis were younger and had shorter disease duration. Serious adverse events (AEs) or side-effects were not observed. Adalimumab was effective also in arthritis. Long-term drug survival (i.e. continuation rate on drug) with etanercept (n=105) vs. infliximab (n=104) was at 24 months 68% vs. 68%, and at 48 months 61% vs. 48% (p=0.194 in log-rank analysis). First-line anti-TNF agent was discontinued either due to inefficacy (etanercept 28% vs. infliximab 20%, p=0.445), AEs (7% vs. 22%, p=0.002), or inactive disease (10% vs. 16%, p=0.068). Females, patients with systemic JIA (sJIA), and those taking infliximab as the first therapy were at higher risk for treatment discontinuation. One-third switched to the second anti-TNF agent, which was discontinued less often than the first. In conclusion, in refractory JIA anti-TNFs induced enhanced growth velocity. Four-year treatment survival was comparable between etanercept and infliximab, and switching from first-line to second-line agent a reasonable therapeutic option. During anti-TNF treatment, one-third with JIA-associated anterior uveitis improved.
  • Häkkinen, Hanna (2004)
    Horizontal restrictions of competition can take different forms – the most obvious being a price cartel, where producers directly agree on the prices of their products. Through a contractual agreement the cartel members are able to increase their joint market power, which leads to higher prices, lower output and, eventually, decreased consumer welfare (the conventional argument against monopolies). It has been estimated that the magnitude of the harm from cartels is many billions of dollars annually. The first part of this thesis presents the most important economic contribution made to the analysis of oligopolistic coordination, which includes among others the articles from Green and Porter (1984) and Rotemberg and Saloner (1986). The analysis begins by identifying structural factors that affect the stability and sustainability of collusion. These factors include industry concentration, entry barriers and demand fluctuations. The analysis shows that collusive behaviour is more likely in industries where concentration ratios and entry barriers are high. However, collusion is more difficult to sustain if demand is unstable. The role played by the presence of large levels of inventories and excess capacities is shown to be more ambiguous, which holds true also for product homogeneity. The end of the first part emphasises the role of price transparency and information exchange in sustaining collusive outcomes. The second part of the thesis is about antitrust enforcement against cartels. Since competition authorities rarely have reliable data on firms’ costs, the detection of cartels is difficult. To overcome this problem of asymmetric information, the authorities in both US and EU have adopted so-called leniency programs that grant reduced fines for cartel members that cooperate with the authority, thus helping to reveal the illegal cartel. The analysis follows Motta and Polo (2003), showing that fine reductions may make antitrust enforcement more effective, but only if the authority’s resources are scarce. Since fine reductions also reduce the cost of collusive behaviour, they may – under certain combinations of policy parameters – make collusion even more attractive.