Browsing by Title

Sort by: Order: Results:

Now showing items 7292-7311 of 26198
  • Lindy, Otso (Helsingin yliopisto, 2008)
    The principal aim of this study was to examine diseases characterized by inflammatory injury, especially human arthritides and periodontitis, with specific interest to final effector enzymes of tissue destruction and address the possible future tools to prevent permanent tissue loss. We used biochemical and immunological methods applied to synovial tissue samples, samples of synovial fluid, and samples of peripheral blood. In Study IV, we used established clinical inflammatory injury indicator probing pocket depth and used it to derive a new clinical measure of systemic burden, periodontal inflammatory burden index. In study I, we showed a difference in the effector enzymes of peripheral blood leukocytes and leukocytes from inflamed synovial fluid of rheumatoid arthritis and reactive arthritis patients. The effector enzyme activities were higher in synovial fluid than in peripheral blood. In study II, we showed the presence of collagenase-3 in rheumatoid synovial tissue samples, relative resistance of the enzyme to inhibition in vitro and developed an electrophoretic method for detection of collagenase-3 in presence of collagenase-1. In study III, we carried out an open label study of doxycycline treatment of 12 RA patients. During the treatment period, we observed an improvement in several of the biochemical and psychosocial variables used to assess the status of the patients. In study IV, we showed a clearly lower level of periodontal inflammatory injury in chronic periodontitis patients referred for periodontal treatment. In this cross-sectional pilot study, we showed lower levels of inflammatory injury in periodontitis patients using statin than in those not receiving statin treatment. The difference was of same magnitude in patients using simvastatin or atorvastatin. The weighted index of inflammatory burden, PIBI, which emphasizes the burden imposed by the deepest pathological pockets on the system showed values consistent with a wider scale to ease future studies on the inflammatory burden associated with periodontitis.
  • Tuomainen, Anita (Helsingin yliopisto, 2009)
    Cardiovascular diseases, which presently are considered inflammatory diseases, affect millions of people worldwide. Chronic infections may contribute to the systemic inflammation suggested to increase the risk for cardiovascular diseases. Such chronic infections are periodontitis and Chlamydia pneumoniae infection. They are highly prevalent as approximately 10% of adult population and 30% of people over 50 years old are affected by severe periodontitis and 70-80% of elderly people are seropositive for C. pneumoniae. Our general aim was to investigate the role of infection and inflammation in atherosclerosis both in animal and human studies. We aimed to determine how the two pathogens alter the atherosclerosis-associated parameters, and how they affect the liver inflammation and lipid composition. Furthermore, we evaluated the association between matrix metalloproteinase-8 (MMP-8), a proteinase playing a major role in inflammation, and the future cardiovascular diseases (CVD) events in a population-based cohort. For the animal experiments, we used atherosclerosis-susceptible apolipoprotein E deficient (apoE-/-) mice. They were kept in germ free conditions and fed with a normal chow diet. The bacteria were administered either intravenously (A. actinomycetemcomitans) or intranasally (C. pneumoniae). Several factors were determined from serum as well as from aortic and hepatic tissues. We also determined how cholesterol efflux, a major event in the removal of excess cholesterol from the tissues, and endothelial function were affected by these pathogens. In the human study, serum MMP-8 and its tissue inhibitor (TIMP-1) concentrations were measured and their associations during the follow-up time of 10 years with CVD events were determined. An infection with A. actinomycetemcomitans increased concentrations of inflammatory mediators, MMP production, and cholesterol deposit in macrophages, decreased lipoprotein particle size, and induced liver inflammation. C. pneumoniae infection also elicited an inflammatory response and endothelial dysfunction, as well as induced liver inflammation, microvesicular appearance and altered fatty acid profile. In the population-based cohort, men with increased serum MMP-8 concentration together with subclinical atherosclerosis (carotid artery intima media thickness > 1mm) had a three-fold increased risk for CVD death during the follow-up. The results show that infections with A. actinomycetemcomitans and C. pneumoniae induce proatherogenic changes, as well as affect the liver. These data therefore support the concept that common infections have systemic effects and could be considered as cardiovascular risk factors. Furthermore, our data indicate that, as an independent predictor of fatal CVD event, serum MMP-8 could have a clinical significance in diagnosing cardiovascular diseases.
  • Lindström, Outi (Helsingin yliopisto, 2010)
    Acute pancreatitis (AP), a common cause of acute abdominal pain, is usually a mild, self-limited disease. However, some 20-30% of patients develop a severe disease manifested by pancreatic necrosis, abscesses or pseudocysts, and/or extrapancreatic complications, such as vital organ failure (OF). Patients with AP develop systemic inflammation, which is considered to play a role in the pathogenesis of multiple organ failure (MOF). OF mimics the condition seen in patients with sepsis, which is characterized by an overwhelming production of inflammatory mediators, activation of the complement system and systemic activation of coagulation, as well as the development of disseminated intravascular coagulation (DIC) syndrome. Vital OF is the major cause of mortality in AP, along with infectious complications. About half of the deaths occur within the first week of hospitalization and thus, early identification of patients likely to develop OF is important. The aim of the present study was to investigate inflammatory and coagulation disturbances in AP and to find inflammatory and coagulation markers for predicting severe AP, and development of OF and fatal outcome. This clinical study consists of four parts. All of patients studied had AP when admitted to Helsinki University Central Hospital. In the first study, 31 patients with severe AP were investigated. Their plasma levels of protein C (PC) and activated protein C (APC), and monocyte HLA-DR expression were studied during the treatment period in the intensive care unit; 13 of these patients developed OF. In the second study, the serum levels of complement regulator protein CD59 were studied in 39 patients during the first week of hospitalization; 12 of them developed OF. In the third study, 165 patients were investigated; their plasma levels of soluble form of the receptor for advanced glycation end products (sRAGE) and high mobility group box 1 (HMGB1) protein were studied during the first 12 days of hos-pitalization; 38 developed OF. In the fourth study, 33 patients were studied on admission to hospital for plasma levels of prothrombin fragment F1+2 and tissue factor pathway inhibitor (TFPI), and thrombin formation capacity by calibrated automated thrombogram (CAT); 9 of them developed OF. Our results showed significant PC deficiency and decreased APC generation in patients with severe AP. The PC pathway defects seemed to be associated with the development of OF. In patients who developed OF, the levels of serum CD59 and plasma sRAGE, but not of HMGB1, were significantly higher than in patients who recovered without OF. The high CD59 levels on admission to the hospital seemed to be predictive for severe AP and OF. The median of the highest sRAGE levels was significantly higher in non-survivors than in survivors. No significant difference between the patient groups was found in the F1+2 levels. The thrombograms of all patients were disturbed in their shape, and in 11 patients the exogenous tissue factor did not trigger thrombin generation at all ( flat curve ). All of the patients that died displayed a flat curve. Free TFPI levels and free/total TFPI ratios were significantly higher in patients with a flat curve than in the others, and these levels were also significantly higher in non-survivors than in survivors. The flat curve in combination with free TFPI seemed to be predictive for a fatal outcome in AP.
  • Jussila, Airi (Helsingin yliopisto, 2014)
    Inflammatory bowel diseases (IBDs), Crohn´s disease (CD) and ulcerative colitis (UC) are characterized by chronic mucosal inflammation and subsequent lesions in the colon or even throughout the gastrointestinal tract with involvement of other organs. They are chronic inflammatory conditions with long-term morbidity and often requiring expensive healthcare. The aetiology of IBD has remained obscure and is thought to be multifactorial. Over the past few years IBD has become a global disease. Western European and North American countries have been traditionally high incidence and prevalence areas. During the last decade, increasing incidence rates has also been observed in Eastern Europe and Asia. It has been suggested that the incidence of IBD has stabilized or slightly increased in Western countries with even decreasing incidence rates for UC in some Western countries. However, new epidemiological data suggest that the incidence and prevalence of the diseases are still increasing in most countries, including Western countries. A North-South gradient has been identifiedfor IBD. In Europe, higher incidence rates have been found in Northern countries. In several countries including the USA, UK and France, North-South gradients have also been reported. Patients with long-lasting IBD, both UC and CD colitis, have been at increased risk of developing colorectal cancer (CRC) and CD patients are at increased risk of small intestine cancer. In most recent studies the risk of CRC has decreased and in some studies no increased risk of CRC has been seen in IBD overall. Male sex, young age at diagnosis, extensive colitis and primary sclerosing cholangitis (PSC) have been shown to increase the risk. Chronic colonic inflammation in UC or CD results in an increased risk of cell proliferation and colon carcinogenesis. Studies have supported the severity of microscopic inflammation as an independent risk factor for dysplasia and CRC in patients with long-standing UC. Patients with CD are at elevated risk of developing extra-intestinal cancers compared to UC patients, whose risk seems to be similar to that of general population. CD patients are at increased risk of developing cancer of the upper gastrointestinal tract, lung, urinary bladder and skin. Patients with UC have a significantly increased risk of liver-biliary cancer, but a decreased risk of lung cancer. Recent studies have shown an increased risk of non‐melanoma skin cancers (NMSCs) in IBD patients, especially in those taking thiopurines. An increased risk of lymphoma has also been observed among IBD patients taking thiopurines. IBD can cause increased mortality. The research on overall and cause-specific mortality in IBD is to some extent contradictory. Earlier studies have documented a slightly increased overall mortality for UC patients compared with general population but most studies have reported no increased mortality risk. In contrast to UC, overall mortality for patients with CD has been increased according to most studies. Among patients with UC mortality from CRCs, gastrointestinal, respiratory and nonalcoholic liver diseases has been increased. The increased mortality among CD patients has been attributed an excess of mortality in gastrointestinal, respiratory, genitourinary, infectious and nonalcoholic liver disease. This thesis aims to evaluate overall burden of IBD in Finland by estimating the nationwide incidence of IBD during the period 2000 2007 and the nationwide prevalence of IBD and changes in the prevalence from 1993 to 2008 by analysing the unique, comprehensive Finnish reimbursement database. Our aim was also to test the North-South gradient hypothesis. We moreover had an opportunity to study vitamin D levels in Finland in the Health 2000 Survey. Our aim was also to assess the long-term risks of malignant diseases and the overall and cause-specific mortality among patients with IBD in a nationwide study in Finland. Finally, our aim was to assess whether the degree of microscopic inflammation is a risk factor for developing dysplasia or CRC in IBD, and to specify the risk for developing dysplasia in patients with no inflammation to better target surveillance in IBD.
  • Järveläinen, Harri (Helsingin yliopisto, 2000)
  • Lindblad, Annika (2010)
    This thesis considers the relationship between inflation and inflation uncertainty in Finland, Germany and Sweden in the past 35 years. The hypotheses by Friedman (1976) and Cukierman and Meltzer (1986) are considered. We also investigate whether the introduction of the common monetary policy on the euro area in 1999 has influenced inflation uncertainty in Finland and Germany. In addition, we examine whether the introduction of inflation targeting in 1993 by the Finnish and Swedish central banks have significantly affected inflation uncertainty. It is commonly accepted, that the main cost related to inflation arises from inflation uncertainty. Friedman (1976) suggested that higher inflation leads to higher inflation uncertainty, and therefore policies lowering inflation should also reduce uncertainty and thus the costs related to inflation. Cukierman and Meltzer (1986) proposed a reversed causality relationship, where higher inflation uncertainty leads to higher inflation. These hypotheses are discussed in the theoretical part. Inflation uncertainty is modelled with GARCH-in-mean (GARCH-M) specifications, where the conditional variance of inflation serves as a proxy for inflation uncertainty. The GARCH-M model also allows for determining the direct relationship between inflation and uncertainty. Asymmetric effects of uncertainty to positive and negative inflation shocks are determined with the GJR-GARCH-M model. The CGARCH-M specification, which differs between long term and short term uncertainty, is also utilised. Friedman's hypothesis is broadly accepted in the empirical part of the thesis, while support for the proposition by Cukierman and Meltzer cannot be found. Thus policies lowering and stabilising inflation, such as inflation targeting, should reduce inflation uncertainty. Although some evidence in favour of a decline in inflation uncertainty since inflation targeting was introduced by the Bank of Finland and the Riksbank can be found, the results depend on the preferred specification. In addition, inflation uncertainty seems to have increased rather than decreased in Finland and Germany in connection to the EMU, although the results are diverse and especially for Finland the size of the effect is almost negligible. However, despite the clear decline in average inflation during the past 35 years, no significant decline in inflation uncertainty has occurred in connection to the ECB.
  • Karpansalo, Aleksi (2015)
    Tutkielmassa esitetään kuvailevan vaativuusteorian tulos inflatorisen kiintopistelogiikan ja polynomisen ajan vaativuusluokan yhteydestä. Tuloksen todistamiseen tarvittavat logiikan ja vaativuusteorian pohjatiedot käydään tutkielmassa läpi. Joukko-opin perusteet ja yleiset merkinnät toivotaan lukijalle entuudesta tutuiksi. Inflatorinen kiintopistelogiikka on ensimmäisen kertaluvun logiikan laajennus, johon on lisätty inflatoriseksi kiintopistekvantifioinniksi kutsuttu kaavanmuodostussääntö. Inflatorinen kiintopistekvantifiointi määrittelee relaation induktiivisesti ja sopii hyvin kuvailemaan tietokoneiden iteratiivisia ja rekursiivisia toimenpiteitä. Rajoittumalla äärellisiin järjestettyihin malleihin saadaan inflatorisen kiintopistelogiikan ilmaisuvoima vastaamaan vaativuusteorian polynomisen ajan vaativuusluokkaa. Vaativuusteoriassa käytetään Turingin koneita työkaluna ongelmien ratkaisemiseen tarvittavia resursseja arvioitaessa. Resurssivaativuuksiltaan samankaltaisia ongelmia luokitellaan vaativuusluokkiin. Polynomisen ajan vaativuusluokka on luokka kaikille ongelmille, jotka voidaan ratkaista syötteen pituudesta polynomisesti riippuvassa määrässä Turingin koneen laskennan askelia. Inflatorisen kiintopistelogiikan ja polynomisen ajan vaativuusluokan yhteyden osoittamiseksi tutkielmassa esitetään, kuinka kuvailla logiikan malleja Turingin koneilla ja Turingin koneita logiikan kaavoilla. Tarvittavien työkalujen esittelyjä seuraa tutkielman päätulos: inflatorinen kiintopistelogiikka karakterisoi polynomisen ajan vaativuusluokan. Lopuksi käydään läpi järjestyksen olettamisen tarpeellisuutta.
  • Hämäläinen, Anssi-Petteri (Helsingfors universitet, 2010)
    IBD- ja reumasairaudet ovat elämänlaatua merkittävästi heikentäviä, kroonisia tulehduksellisia sairauksia, joiden keskivaikeiden ja vakavien muotojen hoidossa suoneen annettava biologinen TNF-alfa -tulehdustekijän vasta-aine infliksimabi (Remicade®) on vankassa asemassa. Infliksimabin hyvän tehon kääntöpuolena esiintyy yleisesti haittoja, joista infuusion aikana tai pian sen jälkeen ilmenevät allergistyyppiset reaktiot ovat hoitoa hankaloittava ja jopa vaarallinen alaluokka. Infuusioreaktioiden estoon ei nykyisellään ole todistettavasti tehokkaita keinoja. Parasetamoli ja setiritsiini osoittautuivat tässä käyttötarkoituksessa tehottomiksi. HUS:n Lasten ja nuorten sairaalassa aloitettiin 11.3.2009 hoitokokeilu asetosalisyylihapolla (ASA, Disperin®), annosteltuna painonmukaisesti per os, päämääränä selvittää prospektiivisesti ASA:n käyttömahdollisuudet infuusioreaktioiden ehkäisyssä. Tämän tutkielman aineisto kerättiin esilääkekokeilun alun ja 24.6.2010 välisellä ajalla (yhteensä 67 viikkoa) infliksimabi-infuusiossa Lasten ja nuorten sairaalan osasto 2:lla käyneiden IBD- ja reumapotilaiden asiakirjoista. Vain 1 (0,2 %) ASA:n kanssa annetuista infuusioista johti infuusioreaktioon kun aiemmin parasetamolin ja setiritsiinin kanssa todettiin 11 (2,9 %) reaktiota. GraphPad Prism 5 -ohjelmistolla tehdyn tilastoanalyysin perusteella tulokset osoittavat ASA:n olevan erittäin lupaava infuusioreaktioiden estolääke.
  • Derakhshan, Behrouz (2015)
    Maximizing influence in graphs, typically applied to Social Networks, is the problem of finding a set of nodes with the highest overall influence on the entire graph. In marketing domain for example, it is used to find the set of people who have the highest influence on their local communities. As a result, instead of blindly marketing a product to a large group of people, the product is marketed to this group of selected users, and they will in turn help spreading the word. The problem has been studied extensively, and several state of the art methods have been proposed. But all of these methods have one common flaw, none of them are scalable. Even on small graphs, current methods take extremely long amount of time and introduction of bigger data sets have rendered some of these methods completely useless. Over the past two decades, collection of data has become easier and a very common practice. This is mostly credited to the advancements in hardware and software technologies as well as the introduction of World Wide Web. To overcome issues related to big data sets, large scale data processing platforms have been developed to tackle scalability issues of problems similar to the influence maximization. Most notably are the two frameworks called Hadoop and Spark that contain many features for simple data processing, machine learning and graph processing. In this thesis work, some of the current influence maximization algorithms are implemented in these two frameworks, some new methods are proposed, experiments on graphs of different sizes are performed and the results are reported.
  • Wasenius, Niko (Helsingin yliopisto, 2014)
    The prevalence and incidence of non-communicable diseases, which have been associated with physical inactivity, are increasing worldwide. Thus, there is a great need for understanding possibilities to increase health enhancing physical activity. The main aims of this study were to investigate 1) the effects of a 13-day in-patient rehabilitation intervention and a 12-week exercise intervention on the intensity and volume of daily total physical activity and on its subcategories 2) the effect of exercise intervention on risk factors for type 2 diabetes, and 3) the effect of non-structured leisure-time physical activity (LTPA) on response to exercise training. The study consists of two separate study cohorts. The first data set included subjects (n = 19, 16 women and 3 men) with chronic neck or shoulder pain and who participated in active rehabilitation interventions. The second data set included 144 overweight or obese middle aged men with impaired glucose regulation who were randomly allocated into a non-exercise control (C) group, a Nordic walking (NW) group, and a power type resistance training (RT) group. During the 12-week intervention, the exercise groups performed structured supervised exercises three times a week for 60 minutes. In both datasets intensity and volume of physical activity was measured in metabolic equivalents of tasks (MET) and MET-hours before and during the interventions with combinations of objective measurement, diaries, and questionnaires. In the second dataset changes in glucose, lipid, and liver enzymes metabolism, adipocytokines, body composition, blood pressure, physical capacity, and dietary intake were measured with standard methods. The measurements were performed before and after the intervention. No increase in the volume of total physical activity was observed with either intervention. Both the rehabilitation and NW intervention increased the volume of leisure-time physical activity (LTPA). The weekly increase in the volume of total LTPA (structured exercises + non-structured LTPA) was associated with a decrease in the volume of non-LTPA (other than structured exercise or non-structured exercise). Compared to the control group, especially NW had beneficial effects on the body adiposity tissue and the adipocytokines (leptin and chemerin) associated with the regulation of lipid and glucose metabolism. The intensity of non-structured LTPA during the exercise intervention was found to independently explain 10%, 9%, and 7% of the variation of change in walking speed, body weight, and BMI, respectively. This effect was observed especially after the intensity threshold of 6.3 MET (77% of maximal physical capacity). Thus, interventions aimed to increase physical activity do not automatically increase the volume of total physical activity due to the compensation. They can, however, increase the volume of LTPA, which can subsequently have beneficial health effect on risk factors of type 2 diabetes. Better understanding of the physical activity regulation in response to training can also increase the specificity of the physical activity dosage.
  • Kuoppala, Kaisa (Helsingin yliopisto, 2010)
    The main objective of this thesis was to elucidate the effects of regrowth grass silage and red clover silage on nutrient supply and milk production of dairy cows as compared with primary growth grass silages. In the first experiment (publication I), two primary growth and four regrowth grass silages were harvested at two stages of growth. These six silages were fed to 24 lactating dairy cows with two levels of concentrate allowance. Silage intake and energy corrected milk yield (ECM) responses, and the range in these response variables between the diets, were smaller when regrowth silages rather than primary growth silages were fed. Milk production of dairy cows reflected the intake of metabolizable energy (ME), and no differences in the ME utilization were found between the diets based on silages harvested from primary growth and regrowth. The ECM response to increased concentrate allowance was, on average, greater when regrowth rather than primary growth silages were fed. In the second experiment (publication II), two silages from primary growth and two from regrowth used in I were fed to rumen cannulated lactating dairy cows. Cows consumed less feed dry matter (DM), energy and protein, and produced less milk, when fed diets based on regrowth silages rather than primary growth silages. Lower milk production responses of regrowth grass silage diets were mainly due to the lower silage DM intake, and could not be accounted for by differences in energy or protein utilization. Regrowth grass silage intake was not limited due to neutral detergent fibre (NDF) digestion or rumen fill or passage kinetics. However, lower intake may be at least partly attributable to plant diseases such as leaf spot infections, dead deteriorating material or abundance of weeds, which are all higher in regrowth compared with primary growth, and increase with advancing regrowth. In the third experiment (publications III and IV), red clover silages and grass silages harvested at two stages of growth, and a mixed diet of red clover and grass silages, were fed to five rumen cannulated lactating dairy cows. In spite of the lower average ME intake for red clover diets, the ECM production remained unchanged suggesting more efficient utilisation of ME for red clover diets compared with grass diets. Intake of N, and omasal canal flows of total non-ammonia N (NAN), microbial and non-microbial NAN were higher for red clover than for grass silage diets, but were not affected by forage maturity. Delaying the harvest tended to decrease DM intake of grass silage and increase that of red clover silage. The digestion rate of potentially digestible NDF was faster for red clover diets than for grass silage diets. Delaying the harvest decreased the digestion rate for grass but increased it for red clover silage diets. The low intake of early-cut red clover silage could not be explained by silage digestibility, fermentation quality, or rumen fill but was most likely related to the nutritionally suboptimal diet composition because inclusion of moderate quality grass silage in mixed diet increased silage DM intake. Despite the higher total amino acid supply of cows fed red clover versus grass silage diets, further milk production responses on red clover diets were possibly compromised by an inadequate supply of methionine as evidenced by lower methionine concentration in the amino acid profile of omasal digesta and plasma. Increasing the maturity of ensiled red clover does not seem to affect silage DM intake as consistently as that of grasses. The efficiency of N utilization for milk protein synthesis was lower for red clover diets than for grass diets. It was negatively related to diet crude protein concentration similarly to grass silage diets.
  • Grundström, Sari (2014)
    Tutkimuksen tavoitteena oli selvittää pentuajan ruokinnan vaukutusta lonkkakuvaustulokseen saksanpaimenkoirilla. Työ liittyi laajempaan lonkkatutkimusprojektiin, jonka tarkoituksena oli paikantaa lonkkadysplasiaan vaikuttavia geenejä eri roduissa, sekä selvittää lonkkadysplasian kehittymiseen ja siihen liittyvään kliiniseen oireiluun vaikuttavia ympäristötekijöitä. Kirjallisuuskatsauksessa on tietoa lonkkadysplasiasta ja sairauden syntyyn vaikuttavista ruokinnallisista tekijöistä. Tutkimusosa suoritettiin epidemiologisena eksploratiivisena tapaus-verrokki tutkimuksena. Hypoteesina tässä tutkimuksessa oli aikaisemmin tehdyn pilottikyselyn pohjalta, että raakaruokinta suojaisi koiraa lonkkadysplasian kehitykseltä. Lonkkadysplasia on yksi yleisimmistä ortopedisista sairauksista suurilla koiraroduilla. Se on perinnöllinen sairaus, jonka esiintymiseen myös ympäristötekijöillä on vaikutusta. Ruokinnan ja etenkin ylipainon vaikutusta lonkkadysplasian kehittymiseen on tutkittu paljon suurilla koiraroduilla, ja ylipainon on todettu olevan yksi merkittävimmistä lonkkadysplasian kehitykseen vaikutavista ympäristötekijöistä. Yleisimmin suurten rotujen pentujen ruokintaan suositellaan suurille roduille tarkoitettua teollista pentuajan kuivamuonaa. Muiden ruokintavaihtoehtojen kuten kotiruuan ja raakaruuan vaikutuksesta nivelten kehitykseen on hyvin rajoitetusti tietoa saatavilla. Silti monet omistajista valitsevat tänä päivänä ruokkia koiransa esimerkiksi raakaruualla tai antaa koiralleen raakaruokaa muun ravinnon lisänä. Tutkimusaineisto on peräisin DOGRISK kyselytutkimuksesta, jossa kysyttiin koiran ruokinnasta eri elämänvaiheissa. Tämän tutkimuksen kiinnostuksen kohteena oli ruokinta 2-6kk ja 6-18kk iässä. Tutkimuksen alussa kyselyyn oli tullut vastauksia 2-6 kuukauden ikää koskeviin kysymyksiin 157 ja 6-18 kuukauden ikää koskeviin kysymyksiin 130, koskien saksanpaimenkoiria, joilla kaikilla oli virallinen lonkkakuvaustulos. Tulokset käsiteltiin tilastollisesti ristiintaulukoimalla, Mann-Whitney U -testillä ja pääkomponenttianalyysillä. Tulosten perusteella BARF ruokinta tai raa’an lihan, raakojen sisäelinten, raakojen luiden ja rustojen, raa’an kalan, raa’an kananmunan ja raa’an naudan mahan syöttäminen pennulle osana muuta ruokavaliota suojaa saksanpaimenkoiria lonkkadysplasialta. Toisaalta kypsennetyn lihan sekä kypsennettyjen luiden ja rustojen syöttäminen tutkimuksen mukaan vaikuttaa altistavan lonkkadysplasialle. Tulokset olivat tilastollisesti merkitseviä. Teollisen kuivamuonan syöttäminen oli yleistä sekä tapaus-, että verokkiryhmissä, eikä kuivamuonan syöttämisellä tässä tutkimuksessa havaittu olevan yhteyttä lonkkadysplasiaan. Omistajia oli myös pyydetty arvioimaan, kuinka suuri osa koiran ravinnosta on kuivamuonaa, muuta teollista ruokaa, raakaruokaa ja kotiruokaa. Tulosten perusteella tervelonkkaiset koirat saivat enemmän raakaravintoa kuin lonkkadysplasiaa sairastavat koirat. Pääkomponenttianalyysissä raakaruuista koostunut komponentti oli ainoa komponenteista, joka korreloi merkitsevästi lonkkadysplasian kanssa. Korrelaatio oli negatiivinen tarkoittaen tässä tutkimuksessa suojaavaa vaikutusta. Tulosten varmistamiseksi tarvitaan vielä jatkoanalyysejä ja kliinisiä jatkotutkimuksia.
  • Guo, Yang (Helsingin yliopisto, 2014)
    The literature review deals with the roles of frozen storage, packaging atmosphere and pig diet on lipid oxidation, protein oxidation and other raw meat quality traits. The mechanisms of lipid and protein oxidation and the measurement methodology were also reviewed. The aim of the experimental work was to examine the application of three different packaging formats on the pork longissimus dorsi (LD) chops from two diet groups during frozen storage at -20 °C up to 6 months. Instrumental colour profile, water losses, instrumental tenderness, extent of lipid oxidation and protein oxidation were analysed. The effects of diet, packaging and frozen storage duration were studied. High oxygen modified atmosphere packaging (MAP) induced numerically small but statistically significant oxidation for lipids, and found to impair water-holding and colour profile of the LD chops during frozen storage. However, its effect on protein oxidation measured by free thiol content and protein carbonyl content was not verified. The new diet was found to improve redness (a*) and tenderness (Allo-Kramer shear force). The development of the parameters in the frozen storage could not be ambiguously described, as samples belong to different packaging methods or diet groups behaved differently.
  • Heiniö, Raija-Liisa (Helsingin yliopisto, 2003)
  • Marley, Laura (Helsingfors universitet, 2009)
    The black truffle (Tuber melanosporum) is an inscrutable mushroom. It is widely believed that the physico-chemical properties of a soil are of great importance for it. Its cultivation in the Auvergne region in France is fraught with impediments. Gérard Chevalier (Institut National de la Recherche Agronomique) postulates that soils with higher than 40% clay content would be inauspicious, unless moderated by a compensating effect from increased rock fragments content. The work undertaken should substantiate this hypothesis, and furthermore take inventory of the mycorrhizal status of the 25 truffle orchards, some of which are thirty years old. The results show that 50% of the plantations still house Tuber melanosporum mycorrhizae. Statistical analysis of the collected information vis-à-vis soil analyses and interpretations of soil profiles in relation to production, shows that a high clay content diminishes the chances of success. The results attained are not sufficient to assert the compensatory effect of soil stoniness. This study moreover highlights the significant roles of total carbonate, active carbonate, phosphorus and potassium contents. These results should be considered with caution, since the small size sample consists of “instances” with heterogeneous characteristics, and the soil analysis methodology does not take into account various environmental factors, whose impact could well be significant (for example light conditions in the orchards). Despite these limitations, this study conveys a dual adage, both scientific and technical. For researchers, it brings some additional insights. For those who wish to produce Tuber melanosporum, it confirms an existing potential in Auvergne. By and large, it illuminates the murky manifest countenance of the black truffle.
  • Patokoski, Johanna (Helsingin yliopisto, 2015)
    Volatile organic compounds (VOCs) are known to be key players in the atmospheric processes. They are emitted both from natural and non-biogenic sources. Although the biogenic sources are generally dominant compared with the anthropogenic sources in some circumstances the anthropogenic emissions can dominate e.g. in densely populated areas or during pollution plumes. VOCs are ambient trace gases including a vast group of compounds. Some of the VOCs are very reactive, participating in atmospheric transformation processes e.g. secondary organic aerosol formation and growth. Some VOCs are also known to be harmful air pollutants for humans. Thus VOCs can have direct effects on air quality and secondary effects on climate. In this thesis, the aim was to define sources of VOCs, determine influence of transport and transformation of trace gases and aerosols. VOCs were measured mainly by a real time proton transfer reaction mass spectrometer. In addition, gas and liquid chromatography were used. The measurements were conducted at the rural SMEAR II and the urban background SMEAR III sites. Concentrations of VOCs were observed to have inter-annual, seasonal and diurnal variations due to meteorological factors, photochemistry and different sources. The anthropogenic influence was dominant in winter at both sites, while the biogenic influence with enhanced photochemical reactions increased in spring. The mixing and dilution effect also increased in spring and it led to decreased levels of volume mixing ratios (VMRs) in daytime especially in short-lived compounds. The VMRs of aromatic compounds were lower in spring than in winter due to lesser sources and enhanced photochemistry at both sites. At the urban background site there were more local sources than rural site and thus more variation of the diurnal patterns; higher VMRs of VOCs were observed. At both sites long-range transport was found to be an important source for long-lived VOCs. The source areas of long-lived VOCs were studied with trajectory analysis. Eastern Europe including West Russia was found to be major source area for all studied VOCs. In addition, some of them had specific source areas of their own related e.g. to their use in the solvent industry. During measurements there were two different forest fire episodes in Eastern Europe and a one-day prescribed biomass burning experiment. VMRs of VOCs related to burning were observed to increase during these pollution plumes. Atmospheric oxidation of BVOCs (biogenic VOCs) revealed that monoterpenes and their oxidation products by ozone were limiting factors for nucleation particle growth. Study of total OH reactivity showed that there are a number of unmeasured biogenic compounds which may have effects on the local atmospheric chemical processes. Keywords: variations of VOC concentrations, source analysis, long-range transport, forest fires, atmospheric chemistry