Kasvien sekundääriaineet ja maan hiilen ja typen kierron mikrobiprosessit eri puulajien metsiköissä

The aim of this study was to explore soil microbial activities related to C and N cycling and the occurrence and concentrations of two important groups of plant secondary compounds, terpenes and phenolic compounds, under silver birch (Betula pendula Roth), Norway spruce (Picea abies (L.) Karst) and Scots pine (Pinus sylvestris L.) as well as to study the effects of volatile monoterpenes and tannins on soil microbial activities. The study site, located in Kivalo, northern Finland, included ca. 70-year-old adjacent stands dominated by silver birch, Norway spruce and Scots pine. Originally the soil was very probably similar in all three stands. All forest floor layers (litter (L), fermentation layer (F) and humified layer (H)) under birch and spruce showed higher rates of CO2 production, greater net mineralisation of nitrogen and higher amounts of carbon and nitrogen in microbial biomass than did the forest floor layers under pine. Concentrations of mono-, sesqui-, di- and triterpenes were higher under both conifers than under birch, while the concentration of total water-soluble phenolic compounds as well as the concentration of condensed tannins tended to be higher or at least as high under spruce as under birch or pine. In general, differences between tree species in soil microbial activities and in concentrations of secondary compounds were smaller in the H layer than in the upper layers. The rate of CO2 production and the amount of carbon in the microbial biomass correlated highly positively with the concentration of total water-soluble phenolic compounds and positively with the concentration of condensed tannins. Exposure of soil to volatile monoterpenes and tannins extracted and fractionated from spruce and pine needles affected carbon and nitrogen transformations in soil, but the effects were dependent on the compound and its molecular structure. Monoterpenes decreased net mineralisation of nitrogen and probably had a toxic effect on part of the microbial population in soil, while another part of the microbes seemed to be able to use monoterpenes as a carbon source. With tannins, low-molecular-weight compounds (also compounds other than tannins) increased soil CO2 production and nitrogen immobilisation by soil microbes while the higher-molecular-weight condensed tannins had inhibitory effects. In conclusion, plant secondary compounds may have a great potential in regulation of C and N transformations in forest soils, but the real magnitude of their significance in soil processes is impossible to estimate.Kasvien tuottamien tiettyjen sekundääristen yhdisteiden on havaittu vaikuttavan maan hiilen ja typen kierron prosesseihin. Tämän tutkimuksen tarkoituksena oli selvittää mahdollisia eroja metsämaan hiilen ja typen kiertoon liittyvissä mikrobiaktiivisuuksissa sekä kahden tärkeän kasvien sekundääriyhdisteryhmän, terpeenien ja fenolisten yhdisteiden, pitoisuuksissa koivikko-, kuusikko- ja männikkömaassa, sekä tutkia, miten maan altistaminen haihtuville monoterpeeneille tai fenolisiin yhdisteisiin kuuluville tanniineille vaikuttaa maan mikrobiaktiivisuuksiin. Tutkimuksessa käytetty puulajikoe sijaitsee Kivalossa, Pohjois-Suomessa, ja käsittää vierekkäiset, alun perin samanlaiselle maaperälle perustetut noin 70-vuotiaat metsiköt, joiden pääpuulajit ovat rauduskoivu, kuusi ja mänty. Maan hiilen ja typen mineralisaationopeudet sekä mikrobibiomassan hiilen ja typen määrät olivat korkeampia koivikko- ja kuusikkomaan orgaanisen kerroksen kaikissa eri osissa, eli karike- (L), multautumis- (F) ja humusainekerroksessa (H), verrattuna männikkömaahan. Mono-, seskvi-, di- ja triterpeenien pitoisuudet olivat selvästi korkeampia havupuumaissa kuin koivikkomaassa, kun taas vesiliukoisten totaalifenolien sekä tanniinien pitoisuudet olivat korkeampia tai vähintään yhtä korkeita kuusikko- kuin koivikko- tai männikkömaassa. Erot maan mikrobiaktiivisuuksissa sekä sekundääriyhdisteiden pitoisuuksissa olivat puulajien välillä yleisesti ottaen pienempiä H-kerroksessa kuin ylemmissä kerroksissa. Hiilen mineralisaationopeus sekä hiilen määrä maan mikrobibiomassassa korreloivat positiivisesti maan vesiliukoisten totaalifenolien sekä tanniinien pitoisuuden kanssa, viitaten siihen, että näiden yhdisteiden pitoisuus maassa voi toimia indikaattorina sille, kuinka pitkälle maan orgaanisen aineksen hajoaminen on edennyt. Terpeenit saattavat puolestaan vaikuttaa maan mikrobiaktiivisuuksia heikentävästi, sillä matalimmat mikrobiaktiivisuudet havaittiin runsaasti terpeenejä sisältävässä männikkömaassa, kun taas aktiivisessa koivikkomaassa terpeenien pitoisuudet olivat hyvin matalat. Haihtuvat monoterpeenit sekä kuusen ja männyn neulasista eristetyt tanniinit vaikuttivat maan hiilen ja typen kierron prosesseihin, mutta vaikutukset riippuivat yhdisteestä ja sen molekyylirakenteesta. Monoterpeenit vähensivät epäorgaanisen typen määrää maassa ja niillä oli mahdollisesti myrkyllinen vaikutus osaan maan mikrobeista, kun taas osa maan mikrobeista näytti voivan käyttää monoterpeeneitä hiilen lähteenään. Molekyylipainoltaan kevyemmät tanniinit (sekä muut kevyemmät yhdisteet) näyttivät olevan hiilen lähteitä maan mikrobeille, kun taas molekyylipainoltaan raskaammilla tanniineilla oli mikrobien toimintaa estäviä vaikutuksia. Kaiken kaikkiaan kasvien sekundääriyhdisteillä saattaa olla hyvinkin suuri rooli metsämaan hiilen ja typen kierron säätelyssä, mutta niiden merkityksen todellista suuruusluokkaa on mahdoton arvioida

Ramsay Hunt syndrome : long-term facial palsy outcome assessed face-to-face by three different grading scales and compared to patient self-assessment

Purpose To determine the long-term facial palsy outcome of Ramsay Hunt Syndrome by face-to-face grading by House-Brackmann Grading System, Facial Nerve Grading System 2.0, and Sunnybrook Facial Grading System concomitantly. To compare the applicability of the grading scales. To compare patients' self-assessed facial palsy outcome results to gradings performed by the investigator. To compare the face-to-face assessed facial palsy outcome to the initial palsy grade. Methods Fifty-seven patients self-assessed their facial palsy outcome and came to a one-time follow-up visit. The palsy outcome was graded by one investigator using the three above-mentioned grading systems concomitantly. The median time from syndrome onset to follow-up visit was 6.6 years. Result A good long-term face-to-face assessed palsy outcome was enjoyed by 84% of the patients. Trying to assess only one House-Brackmann grade to represent the palsy outcome was impossible for most patients. Facial Nerve Grading System 2.0 worked better, but needed adjustments and certain sequelae findings needed to be neglected for it to be executable. The Sunnybrook system worked the best. Nearly 20% of the patients assessed themselves differently from the investigator: both better and worse. Conclusion The Sunnybrook scale was the most applicable system used. With antiviral medication, the outcome of facial palsy in Ramsay Hunt syndrome starts to resemble that of Bell's palsy and emphasizes the importance of recognizing the syndrome and treating it accordingly. The results give hope to patients instead of the gloomy prospects that have stigmatized the syndrome.Peer reviewe

Ramsay Hunt syndrome : characteristics and patient self-assessed long-term facial palsy outcome

Purpose To explore the characteristics, medical treatments, and long-term facial palsy outcome in Ramsay Hunt syndrome. Methods Patient questionnaire including self-assessment of long-term facial palsy outcome and retrospective chart review. Initial facial palsy grade was compared to self-assessed or patient record stated palsy outcome. Occurrence of different characteristics (blisters, hearing loss, vertigo, etc.) of the syndrome were assessed. Results Altogether 120 patients were included of which 81 answered the questionnaire. All but one patient had received virus medication (aciclovir, valaciclovir), and half received simultaneous corticosteroids. If the medication was started within 72 h of Ramsay Hunt diagnosis, facial palsy recovered totally or with only slight sequelae in over 80% of the patients. Only a minority of the patients experienced varicella blisters simultaneously with facial palsy, blisters more often preceded or followed the palsy. Approximately 20% of the patients had their blisters in hidden places in the ear canal or mouth. Conclusions The long-term outcome of facial palsy in medically treated Ramsay Hunt syndrome was approaching the outcome of Bell's palsy. It is crucial to ask and inform the patient about the blisters and look for them since, more often than not, the blisters precede or follow the palsy and can be in areas not easily seen.Peer reviewe

Factors limiting microbial N2O and CO2 production in a cultivated peatland overlying an acid sulphate subsoil derived from black schist

Factors limiting the production of the greenhouse gases nitrous oxide (N2O) and carbon dioxide (CO2) were investigated in three incubation experiments conducted with soil from top- and subsoil horizons of a peatland which had an acid sulphate mineral subsoil derived from black schists. The effect of moisture was investigated by equilibrating undisturbed soil samples from three horizons (H-2, Cg and Cr) at -10, -60 or -100 cm matric potential and measuring the gas production. In the second experiment, the effects of temperature and various substrates were studied by incubating disturbed soil samples in aerobic conditions at 5 or 20 degrees C, and measuring basal respiration and N2O production before and after adding water, glucose or ammonium into the soil. In the third experiment, the effects of added glucose and/or nitrate on the denitrification in soil samples from four horizons (H1, H2, Cg and Cr were investigated by acetylene inhibition and monitoring of N2O production during a 48-h anaerobic incubation. The production of CO2 in the topmost peat horizon was largest at -10 cm matric potential, and it was larger than those in the mineral subsoil also at -60 and -100 cm potentials. In contrast, drainage seemed to increase N2O production, whereas in the wettest condition the production of N2O in the mineral subsoil was small and the peat horizon was a sink of N2O. Lowering of temperature (from 20 degrees C to 5 degrees C) decreased CO2 production, as expected, but it had almost no role in the production of N2O in aerobic conditions. Glucose addition increased the aerobic production of CO2 in peat, but it had a minor effect in the mineral horizons. Lack of C source (glucose) was limiting anaerobic N2O production in the uppermost peat horizon, while in all other horizons, nitrate proved to be the most limiting factor. It is concluded that peatlands with black schist derived acid sulphate subsoil horizons, such as in this study, have high microbial activity in the peaty topsoil horizons but little microbial activity in the mineral subsoil. These findings are contrary to previous results obtained in sediment-derived acid sulphate soils.Peer reviewe

Pulp mill sludges as a solution for reducing the risk of mineral nitrogen leaching from agriculture

Nitrogen (N) from agricultural systems contributes to the eutrophication of waterbodies through leaching. Incorporating organic material with a high carbon-to-nitrogen (C/N) ratio, such as mixed pulp mill sludges (PMSs), into the soil in autumn could reduce the amount of leachable N. This study tested the potential of composted and lime-stabilised mixed PMSs (CPMS and LPMS) in reducing the concentration of mineral N in the soil, and thus the risk of N leaching from arable land in the boreal region using a two-year field experiment. To better understand the mechanisms of the PMSs for influencing mineral N concentration in soil, the impact of PMSs with different quality on the reactions of N in the soil was investigated in a laboratory incubation study. In the field experiment, nitrate-N (NO3--N) concentration was lower with PMSs compared to mineral fertilisation and the control during the first autumn and the following spring after PMS application. The undersowing of Italian ryegrass reduced the NO3--N concentration in the soil during the first autumn. In the incubation experiment, PMSs reduced the soil ammonium-N (NH4+-N) concentration at the beginning of the experiment and the soil NO3--N concentration throughout the experiment compared to a mineral fertiliser treatment and an organic fertiliser. Increased soil respiration in PMS-treated soils indicated increase in microbial activity, and thus immobilisation of soil NO3--N and NH4+-N due to PMSs addition. These results suggest that PMSs have the potential to reduce N leaching from agricultural soils. However, the immobilisation of N must be considered when planning the nutrient requirements of the following crops

Soil organic carbon and clay content as deciding factors for net nitrogen mineralization and cereal yields in boreal mineral soils

To achieve appropriate yield levels, inherent nitrogen (N) supply and biological N fixation are often complemented by fertilization. To avoid economic losses and negative environmental impacts due to over-application of N fertilizer, estimation of the inherent N supply is critical. We aimed to identify the roles of soil texture and organic matter in N mineralization and yield levels attained in cereal cultivation with or without N fertilization in boreal mineral soils. First, the net N mineralization and soil respiration were measured by laboratory incubation with soil samples varying in clay and organic carbon (C) contents. Secondly, to estimate the inherent soil N supply under field conditions, both unfertilized and fertilized cereal yields were measured in fields on clay soils (clay 30-78%) and coarse-textured soils (clay 0-28%). In clay soils (C 2.5-9.0%), both the net N mineralization and the cereal yields (without and with fertilization) decreased with increasing clay/C ratio. Moreover, in soils with high clay/C ratio, the agronomic N use efficiency (additional yield per kg of fertilizer N) varied considerably, indicating the presence of growth limitations other than N. In coarse-textured soils, the yield increase attained by fertilization increased with increasing organic C. Our results indicate that for clay soils in a cool and humid climate, the higher the clay content, the more organic C is needed to produce reasonable yields and to ensure efficient use of added nutrients without high N losses to the environment. For coarse soils having a rather high mean organic C of 2.3%, the organic C appeared to improve agronomic N use efficiency. For farmers, simple indicators such as the clay/C ratio or the use of non-N-fertilized control plots may be useful for site-specific adjustment of the rates of N fertilization. Highlights We aimed to identify simple indicators of inherent soil N supply applicable at the farm level. In clay soils, the net N mineralization was found to correlate negatively with the clay/C ratio. In coarse-textured soils, agronomic N use efficiency improved with increasing soil organic C. Clay soils with high clay/C ratio are at risk of low yield levels.Peer reviewe

Antiangiogenic AAV2 gene therapy with a truncated form of soluble VEGFR-2 reduces the growth of choroidal neovascularization in mice after intravitreal injection

Pathological angiogenesis related to neovascularization in the eye is mediated through vascular endothelial growth factors (VEGFs) and their receptors. Ocular neovascular-related diseases are mainly treated with anti-VEGF agents. In this study we evaluated the efficacy and safety of novel gene therapy using adeno associated virus 2 vector expressing a truncated form of soluble VEGF receptor-2 fused to the Fc-part of human IgG1 (AAV2-sVEGFR-2-Fc) to inhibit ocular neovascularization in laser induced choroidal neovascularization (CNV) in mice. The biological activity of sVEGFR-2-Fc was determined in vitro. It was shown that sVEGFR-2-Fc secreted from ARPE-19 cells was able to bind to VEGF-A165 and reduce VEGF-A165 induced cell growth and survival. A single intravitreal injection (IVT) of AAV2-sVEGFR-2-Fc (1 mu l, 4.7 x 1012 vg/ml) one-month prior laser photocoagu-lation did not cause any changes in the retinal morphology and significantly suppressed fluorescein leakage at 7, 14, 21 and 28 days post-lasering compared to controls. Macrophage infiltration was observed after the injection of both AAV2-sVEGFR-2-Fc and PBS. Our findings indicate that AAV2 mediated gene delivery of the sVEGFR-2-Fc efficiently reduces formation of CNV and could be developed to a therapeutic tool for the treatment of retinal diseases associated with neovascularization.Peer reviewe

Association between overall diet quality and postmenopausal breast cancer risk in five Finnish cohort studies

There is limited evidence for any dietary factor, except alcohol, in breast cancer (BC) risk. Therefore, studies on a whole diet, using diet quality indices, can broaden our insight. We examined associations of the Nordic Diet (mNDI), Mediterranean diet (mMEDI) and Alternative Healthy Eating Index (mAHEI) with postmenopausal BC risk. Five Finnish cohorts were combined including 6374 postmenopausal women with dietary information. In all, 8-9 dietary components were aggregated in each index, higher total score indicating higher adherence to a healthy diet. Cox proportional hazards regression was used to estimate the combined hazard ratio (HR) and 95% confidence interval (CI) for BC risk. During an average 10-year follow-up period, 274 incident postmenopausal BC cases were diagnosed. In multivariable models, the HR for highest vs. lowest quintile of index was 0.67 (95 %CI 0.48-1.01) for mNDI, 0.88 (0.59-1.30) for mMEDI and 0.89 (0.60-1.32) for mAHEI. In this combined dataset, a borderline preventive finding of high adherence to mNDI on postmenopausal BC risk was found. Of the indices, mNDI was more based on the local food culture than the others. Although a healthy diet has beneficially been related to several chronic diseases, the link with the etiology of postmenopausal BC does not seem to be that obvious.Peer reviewe

Testaa eroriskisi

Kailaheimo, S. + Yle (2018) 12.11.2018 Testaa eroriskisi. (Tutkimuksiin perustuva Internet-kysely) YLE-verkkosivut. https://yle.fi/uutiset/3-10471586 </p

Carbon guide : An outlook on carbon in soil and on carbon cultivation

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