469 research outputs found

    Pohjoisten puuttomien soiden funktionaaliset kasviryhmät ja niiden vaikutus hiilenkiertoon

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    Tiivistelmä. Pohjoiset suot peittävät maapallon pinta-alasta vain noin 3 % mutta varastoivat kolmasosan (500 Gt) maapallon hiilestä. Suot toimivat hiilidioksidin nieluina, koska kylmät, kosteat ja hapettomat olosuhteet hidastavat kasvikarikkeen hajotusta, mikä edistää turpeen kerrostumista. Samat olosuhteet ylläpitävät hiilidioksidia 25-kertaa voimakkaamman kasvihuonekaasun, metaanin, tuottamista. Suon kasviyhteisössä hallitsevat funktionaaliset kasviryhmät säätelevät soiden hiilenkierron prosesseja. Tutkielmassa tarkastelen pohjoisten puuttomien soiden tyypillisiä funktionaalisia kasviryhmiä — sammalia, varpuja, saroja, heiniä ja ruohoja — sekä sitä, miten kasvien eri ominaisuudet vaikuttavat suon hiilidioksidi- ja metaanivuohon. Lisäksi tarkastelen, miten ympäristönmuutokset, kuten ilmastonmuutoksen aiheuttama lämpötilan nousu, voivat vaikuttaa suokasvillisuuteen ja sitä kautta suon kykyyn toimia hiilinieluna. Funktionaaliset kasviryhmät vaikuttavat suon hiilidioksidivuohon suoraan yhteyttämällä ja hengittämällä sekä epäsuorasti erittämällä hiiliyhdisteitä. Sarat ja ruohot, joilla on korkeampi tuottavuus, sitovat enemmän hiiltä, mutta toisaalta vapauttavat yleensä enemmän juurieritteitä ja tuottavat helposti hajotettavaa kariketta, jotka kiihdyttävät hajotusta ja hiilidioksidin vapautumista turpeesta verrattuna rahkasammaliin ja varpuihin. Juurieritteet ovat helposti hajotettavia yhdisteitä ja edistävät metaanin muodostumista turpeen syvemmissä hapettomissa kerroksissa. Kasveista erityisesti syväjuuriset sarakasvit voivat lisätä metaanin vapautumista kuljettamalla metaania juurten, varren ja lehtien kautta ilmakehään, jolloin metaani ei muutu hiilidioksidiksi turpeen hapekkaassa kerroksessa. Toisaalta metaania kuljettavat kasvit lisäävät myös hapen kulkeutumista turpeeseen, mikä voi lisätä metaanin hapettumista hiilidioksidiksi ja rajoittaa näin suon metaanipäästöjä. Hiilen sitoutumisen ja vapautumisen välinen tasapaino on herkkä ja ihmistoiminnan aiheuttamien muutosten, kuten ilmaston lämpenemisen, voidaan odottaa vaikuttavan funktionaalisten kasviryhmien toimintaan ja näin soiden hiilinieluun lähitulevaisuudessa. Korkeamman vuotuisen lämpötilan ja kasvukauden pitenemisen on ennustettu lisäävän pohjoisilla soilla putkilokasveja sammalten kustannuksella, mikä on huolestuttavaa soiden hiilenkierron kannalta ottaen huomioon rahkasammalten merkityksen hiilensidonnassa

    Is Diversity the Missing Link in Coastal Fisheries Management?

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    Fisheries management has historically focused on the population elasticity of target fish based primarily on demographic modeling, with the key assumptions of stability in environmental conditions and static trophic relationships. The predictive capacity of this fisheries framework is poor, especially in closed systems where the benthic diversity and boundary effects are important and the stock levels are low. Here, we present a probabilistic model that couples key fish populations with a complex suite of trophic, environmental, and geomorphological factors. Using 41 years of observations we model the changes in eastern Baltic cod (Gadus morhua), herring (Clupea harengus), and Baltic sprat (Sprattus sprattus balticus) for the Baltic Sea within a Bayesian network. The model predictions are spatially explicit and show the changes of the central Baltic Sea from cod-to sprat-dominated ecology over the 41 years. This also highlights how the years 2004 to 2014 deviate in terms of the typical cod–environment relationship, with environmental factors such as salinity being less influential on cod population abundance than in previous periods. The role of macrozoobenthos abundance, biotopic rugosity, and flatfish biomass showed an increased influence in predicting cod biomass in the last decade of the study. Fisheries management that is able to accommodate shifting ecological and environmental conditions relevant to biotopic information will be more effective and realistic. Non-stationary modelling for all of the homogeneous biotope regions, while acknowledging that each has a specific ecology relevant to understanding the fish population dynamics, is essential for fisheries science and sustainable management of fish stocks

    Anticoagulation Therapy After Biologic Aortic Valve Replacement

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    Objectives: Thromboembolism prophylaxis after biologic aortic valve replacement (BAVR) is recommended for 3 months postoperatively. We examined the continuation of oral anticoagulation (OAC) treatment and its effect on the long-term prognosis after BAVR.Methods: We used nation-wide register data from 4,079 individuals who underwent BAVR. We examined the association between warfarin and the non-vitamin K antagonist oral anticoagulant use with death, stroke and major bleeding in 2010 – 2016.Results: The risk of stroke was higher (HR 2.39, 95% CI 1.62 – 3.53, p < 0.001) and the risk of death was lower (HR 0.79, 95% CI 0.65 – 0.96, p = 0.016) in OAC-users compared to individuals without OAC. We observed no significant associations between OAC use and bleeding risk.Conclusion: OAC use after BAVR was associated with increased risk of stroke and decreased risk of death. These observational findings warrant validation in randomized controlled trials before any clinical conclusions can be drawn

    Cognitive impairment is not uncommon in patients with biallelic RFC1 AAGGG repeat expansion, but the expansion is rare in patients with cognitive disease

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    Introduction: The biallelic repeat expansion (AAGGG)(exp) in RFC1 causes cerebellar ataxia, neuropathy, and vestibular areflexia syndrome (CANVAS). Recently, cognitive impairment has been reported in patients with CANVAS and a broader neurodegenerative process associated with RFC1 has been suggested. Furthermore, rare cases of multiple system atrophy, Parkinson's disease, amyotrophic lateral sclerosis or CANVAS with features of dementia with Lewy bodies have been found. Objective: We hypothesized that the biallelic (AAGGG)(exp) is associated with neurodegeneration manifested as cognitive symptoms and that atypical RFC1 disease may be found among patients with cognitive disorder. Methods: Clinical data on nine patients with biallelic (AAGGG()exp) were reviewed and 564 patients with Alz-heimer's disease or frontotemporal dementia (FTD) were investigated for biallelic RFC1 (AAGGG)(exp). Results: Five patients with biallelic (AAGGG)(exp) were found with a cognitive impairment and in four of them the phenotype resembled FTD. However, biallelic (AAGGG)(exp) was not detected among patients with Alzheimer's disease or FTD. Conclusion: Cognitive impairment is a feature in patients with the biallelic (AAGGG)(exp), but the pathogenic expansion seems to be rare in patients with dementia. Studies on patients with diverse phenotypes would be useful to further explore the involvement of RFC1 in neuronal degeneration and to identify atypical phenotypes, which should be taken into account in clinical practice.Peer reviewe

    Genome-wide association study of nocturnal blood pressure dipping in hypertensive patients

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    Abstract Background Reduced nocturnal fall (non-dipping) of blood pressure (BP) is a predictor of cardiovascular target organ damage. No genome-wide association studies (GWAS) on BP dipping have been previously reported. Methods To study genetic variation affecting BP dipping, we conducted a GWAS in Genetics of Drug Responsiveness in Essential Hypertension (GENRES) cohort (n = 204) using the mean night-to-day BP ratio from up to four ambulatory BP recordings conducted on placebo. Associations with P < 1 × 10− 5 were further tested in two independent cohorts: Haemodynamics in Primary and Secondary Hypertension (DYNAMIC) (n = 183) and Dietary, Lifestyle and Genetic determinants of Obesity and Metabolic Syndrome (DILGOM) (n = 180). We also tested the genome-wide significant single nucleotide polymorphism (SNP) for association with left ventricular hypertrophy in GENRES. Results In GENRES GWAS, rs4905794 near BCL11B achieved genome-wide significance (β = − 4.8%, P = 9.6 × 10− 9 for systolic and β = − 4.3%, P = 2.2 × 10− 6 for diastolic night-to-day BP ratio). Seven additional SNPs in five loci had P values < 1 × 10− 5. The association of rs4905794 did not significantly replicate, even though in DYNAMIC the effect was in the same direction (β = − 0.8%, P = 0.4 for systolic and β = − 1.6%, P = 0.13 for diastolic night-to-day BP ratio). In GENRES, the associations remained significant even during administration of four different antihypertensive drugs. In separate analysis in GENRES, rs4905794 was associated with echocardiographic left ventricular mass (β = − 7.6 g/m2, P = 0.02). Conclusions rs4905794 near BCL11B showed evidence for association with nocturnal BP dipping. It also associated with left ventricular mass in GENRES. Combined with earlier data, our results provide support to the idea that BCL11B could play a role in cardiovascular pathophysiology

    Haptoglobin Hp1 Variant Does Not Associate with Small Vessel Disease

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    Haptoglobin (Hp) is a plasma protein that binds free hemoglobin and protects tissues from oxidative damage. An Hp2 allele has been associated with an increased risk of cardiovascular complications. On the other hand, recent studies have suggested that Hp1 allele increases risk to develop severe cerebral small vessel disease. We aimed to replicate this finding in a first-ever stroke patient cohort. Hp was genotyped by PCR and gel electrophoresis in the Helsinki Stroke Aging Memory Study in patients with DNA and magnetic resonance imaging (MRI) available (SAM; n = 316). Lacunar infarcts and white matter lesions (WML) classified by Fazekas grading from brain MRI were associated with Hp genotypes. As population controls, we used participants of Cardiovascular diseases-a sub study of Health 2000 Survey (n = 1417). In the SAM cohort, 63.0% of Hp1-1 carriers (n = 46), 52.5% of Hp1-2 carriers (n = 141) and 51.2% of Hp2-2 carriers (n = 129) had severe WML (p = 0.372). There was no difference in severe WMLs between Hp1-1 vs. Hp1-2 and Hp2-2 carriers (p = 0.201). In addition, 68.9% of Hp1-1 carriers (n = 45), 58.5% of Hp1-2 carriers (n = 135), and 61.8% of Hp2-2 carriers (n = 126) had one or more lacunar lesions (p = 0.472). There was no difference in the number of patients with at least one lacunar infarct between Hp1-1 vs. Hp1-2 and Hp2-2 groups (p = 0.322). Neither was there any difference when diabetic patients (type I and II) were examined separately. Hp1 allele is not associated with an increased risk for cerebral small vessel disease in a well-characterized Finnish stroke patient cohort

    Lymphatic endothelium stimulates melanoma metastasis and invasion via MMP14-dependent Notch3 and beta 1-integrin activation

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    Lymphatic invasion and lymph node metastasis correlate with poor clinical outcome in melanoma. However, the mechanisms of lymphatic dissemination in distant metastasis remain incompletely understood. We show here that exposure of expansively growing human WM852 melanoma cells, but not singly invasive Bowes cells, to lymphatic endothelial cells (LEC) in 3D co-culture facilitates melanoma distant organ metastasis in mice. To dissect the underlying molecular mechanisms, we established LEC co-cultures with different melanoma cells originating from primary tumors or metastases. Notably, the expansively growing metastatic melanoma cells adopted an invasively sprouting phenotype in 3D matrix that was dependent on MMP14, Notch3 and beta 1-integrin. Unexpectedly, MMP14 was necessary for LEC-induced Notch3 induction and coincident beta 1-integrin activation. Moreover, MMP14 and Notch3 were required for LEC-mediated metastasis of zebrafish xenografts. This study uncovers a unique mechanism whereby LEC contact promotes melanoma metastasis by inducing a reversible switch from 3D growth to invasively sprouting cell phenotype.Peer reviewe

    Application of non-HDL cholesterol for population-based cardiovascular risk stratification: results from the Multinational Cardiovascular Risk Consortium.

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    BACKGROUND: The relevance of blood lipid concentrations to long-term incidence of cardiovascular disease and the relevance of lipid-lowering therapy for cardiovascular disease outcomes is unclear. We investigated the cardiovascular disease risk associated with the full spectrum of bloodstream non-HDL cholesterol concentrations. We also created an easy-to-use tool to estimate the long-term probabilities for a cardiovascular disease event associated with non-HDL cholesterol and modelled its risk reduction by lipid-lowering treatment. METHODS: In this risk-evaluation and risk-modelling study, we used Multinational Cardiovascular Risk Consortium data from 19 countries across Europe, Australia, and North America. Individuals without prevalent cardiovascular disease at baseline and with robust available data on cardiovascular disease outcomes were included. The primary composite endpoint of atherosclerotic cardiovascular disease was defined as the occurrence of the coronary heart disease event or ischaemic stroke. Sex-specific multivariable analyses were computed using non-HDL cholesterol categories according to the European guideline thresholds, adjusted for age, sex, cohort, and classical modifiable cardiovascular risk factors. In a derivation and validation design, we created a tool to estimate the probabilities of a cardiovascular disease event by the age of 75 years, dependent on age, sex, and risk factors, and the associated modelled risk reduction, assuming a 50% reduction of non-HDL cholesterol. FINDINGS: Of the 524 444 individuals in the 44 cohorts in the Consortium database, we identified 398 846 individuals belonging to 38 cohorts (184 055 [48·7%] women; median age 51·0 years [IQR 40·7-59·7]). 199 415 individuals were included in the derivation cohort (91 786 [48·4%] women) and 199 431 (92 269 [49·1%] women) in the validation cohort. During a maximum follow-up of 43·6 years (median 13·5 years, IQR 7·0-20·1), 54 542 cardiovascular endpoints occurred. Incidence curve analyses showed progressively higher 30-year cardiovascular disease event-rates for increasing non-HDL cholesterol categories (from 7·7% for non-HDL cholesterol <2·6 mmol/L to 33·7% for ≥5·7 mmol/L in women and from 12·8% to 43·6% in men; p<0·0001). Multivariable adjusted Cox models with non-HDL cholesterol lower than 2·6 mmol/L as reference showed an increase in the association between non-HDL cholesterol concentration and cardiovascular disease for both sexes (from hazard ratio 1·1, 95% CI 1·0-1·3 for non-HDL cholesterol 2·6 to <3·7 mmol/L to 1·9, 1·6-2·2 for ≥5·7 mmol/L in women and from 1·1, 1·0-1·3 to 2·3, 2·0-2·5 in men). The derived tool allowed the estimation of cardiovascular disease event probabilities specific for non-HDL cholesterol with high comparability between the derivation and validation cohorts as reflected by smooth calibration curves analyses and a root mean square error lower than 1% for the estimated probabilities of cardiovascular disease. A 50% reduction of non-HDL cholesterol concentrations was associated with reduced risk of a cardiovascular disease event by the age of 75 years, and this risk reduction was greater the earlier cholesterol concentrations were reduced. INTERPRETATION: Non-HDL cholesterol concentrations in blood are strongly associated with long-term risk of atherosclerotic cardiovascular disease. We provide a simple tool for individual long-term risk assessment and the potential benefit of early lipid-lowering intervention. These data could be useful for physician-patient communication about primary prevention strategies. FUNDING: EU Framework Programme, UK Medical Research Council, and German Centre for Cardiovascular Research

    Diabetes and heart failure associations in women and men: results from the MORGAM consortium

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    Background: Diabetes and its cardiovascular complications are a growing concern worldwide. Recently, some studies have demonstrated that relative risk of heart failure (HF) is higher in women with type 1 diabetes (T1DM) than in men. This study aims to validate these findings in cohorts representing five countries across Europe. Methods: This study includes 88,559 (51.8% women) participants, 3,281 (46.3% women) of whom had diabetes at baseline. Survival analysis was performed with the outcomes of interest being death and HF with a follow-up time of 12 years. Sub-group analysis according to sex and type of diabetes was also performed for the HF outcome. Results: 6,460 deaths were recorded, of which 567 were amongst those with diabetes. Additionally, HF was diagnosed in 2,772 individuals (446 with diabetes). A multivariable Cox proportional hazard analysis showed that there was an increased risk of death and HF (hazard ratio (HR) of 1.73 [1.58–1.89] and 2.12 [1.91–2.36], respectively) when comparing those with diabetes and those without. The HR for HF was 6.72 [2.75–16.41] for women with T1DM vs. 5.80 [2.72–12.37] for men with T1DM, but the interaction term for sex differences was insignificant (p for interaction 0.45). There was no significant difference in the relative risk of HF between men and women when both types of diabetes were combined (HR 2.22 [1.93–2.54] vs. 1.99 [1.67–2.38] respectively, p for interaction 0.80). Conclusion: Diabetes is associated with increased risks of death and heart failure, and there was no difference in relative risk according to sex
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