660 research outputs found
Ingrowth, survival and height growth of small trees in uneven-aged Picea abies stands in southern Finland
The purpose of the study was to analyse height growth, mortality, and ingrowth of individual small-sized trees in uneven-aged spruce-dominated stands. It was based on experimental data from 16 stands for a 15-year observation period including four measurements with a 5-year interval. In the data of this study, the heights of small-sized trees varied from 0.1 to about 9 m. Results showed that the growth of small trees was rather slow, particularly in the smallest size classes. With average growth rates it would take about 60 years for a freshly emerged spruce germinant to achieve 1.3 m in height. The stand density, site quality and selection cuttings affected the growth of small-sized spruces. Average five-year mortality rates for spruce, birch and pine were 17.0%, 40.9% and 33.9%, respectively. Annual ingrowth rates with the threshold height of 1.3 m for the three species were on average 30.4, 2.8 and less than 0.1 trees per hectare, respectively. Even if, a selection cutting of modest intensity (25% of basal area removed on average) seemed to have accelerated the growth of small spruces, it is recommended that more intensive harvestings be applied to enhance the survival and growth of small spruces. It is also concluded that shade intolerant species like birch and pine do not seem to be capable of developing into viable undergrowth in spruce selection stands with their current levels of stand density
Formation of canker lesions on stems and black scurf on tubers in experimentally inoculated potato plants by isolates of AG2-1, AG3 and AG5 of Rhizoctonia solani: a pilot study and literature review
Development of black scurf on potato tubers (cv. Nicola) was compared in plants inoculated with isolates of Rhizoctonia solani of three anastomosis groups (AG2-1, AG3 and AG5) which occur in potato crops in Finland. All isolates induced stem canker lesions but only isolates of AG3 formed efficiently black scurf on progeny tubers. Among the AG2-1 and AG5 isolates tested, only one AG2-1 isolate formed a few sclerotia on 13.5 % of the progeny tubers in one experiment. The data indicate that isolates of AG3 differ from those of AG2-1 and AG5 in having a higher ability to form sclerotia on tubers. Therefore, while AG2-1 and AG5 isolates have a broader host range, AG3 is more efficient in producing black scurf, which provides this anastomosis group with more efficient means of dissemination on seed potatoes. These differences probably explain the predominance of AG3 (98.9 % of isolates) in potato crops in Finland and other northern potato production areas
Assessment of Time-Dependent Platelet Activation Using Extracellular Vesicles, CD62P Exposure, and Soluble Glycoprotein V Content of Platelet Concentrates with Two Different Platelet Additive Solutions
Novel analytical measures are needed to accurately monitor the properties of platelet concentrates (PCs). Since activated platelets produce platelet-derived extracellular vesicles (EVs), analyzing EVs of PCs may provide additional information about the condition of platelets. The prospect of using EVs as an auxiliary measure of platelet activation state was investigated by examining the effect of platelet additive solutions (PASs) on EV formation and platelet activation during PC storage. The time-dependent activation of platelets in PCs with PAS-B or with the further developed PAS-E was compared by measuring the exposure of CD62P by flow cytometry and the content of soluble glycoprotein V (sGPV) of PCs by an immunoassay. Changes in the concentration and size distribution of EVs were determined using nanoparticle tracking analysis. A time-dependent increase in platelet activation in PCs was demonstrated by increased CD62P exposure, sGPV content, and EV concentration. Using these strongly correlating parameters, PAS-B platelets were shown to be more activated compared to PAS-E platelets. Since the EV concentration correlated well with the established platelet activation markers CD62P and sGPV, it could potentially be used as a complementary parameter for platelet activation for PCs. More detailed characterization of the resulting EVs could help to understand how the PC components contribute the functional effects of transfused PCs.Peer reviewe
Effects of overstory tree density, site preparation, and ground vegetation on natural Scots pine seedling emergence and survival in northern boreal pine forests
Natural regeneration is a commonly used forest regeneration method in northern Finland. It is not known, however, what would be the optimal overstory density and ground vegetation composition for seedling emergence and survival, and if site preparation is needed to accompany overstory density manipulation. We studied the effects of overstory density (unthinned control and thinning to 50,150, and 250 trees.ha(-1)) and ground vegetation removal (mechanical site preparation with disc trenching) on the number of naturally germinated pine seedlings and survival of individual seedlings over a period of 8 to 11 years. Bare mineral soil was a superior seedbed compared to intact vegetation cover, even though the mortality rate was high on mineral soil. Greater cover of lingonberry, crowberry, and slash had a negative effect on seedling number. Seedling mortality was initially high (60% died during the first 2 years) but decreased throughout the first 5 years. The survival rate of seedlings located in the mineral soil of the upper part of the disc trencher track was twice as high as that of seedlings located in the lower part of the track. High coverage of hair mosses (Polytrichum spp.) was associated with poorer seedling survival. An overstory density of 50-150 trees.ha(-1) with site preparation seems to be an efficient treatment to promote regeneration under these circumstances
Thrombolysis in stroke patients with elevated inflammatory markers
Objective To investigate the prognostic value of white blood cell count (WBC) on functional outcome, mortality and bleeding risk in stroke patients treated with intravenous thrombolysis (IVT). Methods In this prospective multicenter study from the TRISP registry, we assessed the association between WBC on admission and 3-month poor outcome (modified Rankin Scale 3-6), mortality and occurrence of symptomatic intracranial hemorrhage (sICH; ECASS-II-criteria) in IVT-treated stroke patients. WBC was used as continuous and categorical variable distinguishing leukocytosis (WBC > 10 x 10(9)/l) and leukopenia (WBC 10 mg/l) on outcomes. Results Of 10,813 IVT-treated patients, 2527 had leukocytosis, 112 leukopenia and 8174 normal WBC. Increasing WBC (by 1 x 10(9)/l) predicted poor outcome (ORadjusted 1.04[1.02-1.06]) but not mortality and sICH. Leukocytosis was independently associated with poor outcome (ORadjusted 1.48[1.29-1.69]) and mortality (ORadjusted 1.60[1.35-1.89]) but not with sICH (ORadjusted 1.17[0.94-1.45]). Leukopenia did not predict any outcome. In a subgroup, combined leukocytosis and elevated CRP had the strongest association with poor outcome (ORadjusted 2.26[1.76-2.91]) and mortality (ORadjusted 2.43[1.86-3.16]) when compared to combined normal WBC and CRP. Conclusion In IVT-treated patients, leukocytosis independently predicted poor functional outcome and death. Bleeding complications after IVT were not independently associated with leukocytosis.Peer reviewe
Could continuous cover forestry be an economically and environmentally feasible management option on drained boreal peatlands?
Environmental and economic performance of forestry on drained peatlands was reviewed to consider whether continuous cover forestry (CCF) could be a feasible alternative to even-aged management (EM). CCF was regarded feasible particularly because continuously maintaining a tree stand with significant transpiration and interception capacity would decrease the need for ditch network maintenance. Managing CCF forests in such a way that the ground water levels are lower than in clear-cut EM forests but higher than in mature EM forests could decrease greenhouse gas emissions and negative water quality impacts caused both by anoxic redox reactions and oxidation and mineralization of deep peat layers. Regeneration studies indicated potential for satisfactory natural regeneration under CCF on drained peatlands. An economic advantage in CCF over EM is that fewer investments are needed to establish the forest stand and sustain its growth. Thus, even if the growth of trees in CCF forests were lower than in EM forests, CCF could at least in some peatland sites turn out to be a more profitable forest management regime. An advantage of CCF from the viewpoint of socially optimal forest management is that it plausibly reduces the negative externalities of management compared to EM. We propose that future research in drained peatland forests should focus on assessing the economic and environmental feasibility of CCF.Peer reviewe
Viljelymenetelmän, lajikkeen ja siemenperunan seittirupisuuden vaikutus perunaseitin (Rhizoctonia solani) määrään
Siemenen seittirupisuuden (6 tasoa), maaperän ominaisuuksien (monokulttuuri tai luomuviljely) ja lajikkeen (Van Gogh tai Saturna) vaikutusta perunaseitin esiintymiseen tutkittiin vuosina 2003-2005 järjestetyssä kenttäkokeessa. Siemenperunan tautisuuden (seittirupisuuden) lisääntyessä versolaikun määrä kasvoi, varsi- ja mukulaluku pieneni ja sadon määrää ja tärkkelyspitoisuus laski. Myöskin laatu heikkeni, kun vihertyneiden, epämuotoisten ja onttojen mukuloiden osuus sadossa kasvoi. Viljelymenetelmä ei vaikuttanut kovin selvästi seittisyyteen, mutta siemenen seittirupisuuden lisääntyessä seittiruven määrä sadossa lisääntyi ainoastaan luomussa. Van Goghissa oli seittiongelmia hieman enemmän kuin Saturnassa. Erityisesti keskeltä ruskolaikkuisten ja onttojen mukuloiden määrä lisääntyi Van Goghilla selvästi siemenen seittirupisuuden lisääntyessä. Tulokset ovat alustavia ja kattavat kaksi ensimmäistä koevuotta (2003-2004)
Culturing of Selenastrum on diluted composting fluids; conversion of waste to valuable algal biomass in presence of bacteria
© 2017 The AuthorsGrowth and fatty acid production of microalga Selenastrum sp. with associated bacteria was studied in lab-scale experiments in three composting leachate liquids. Nutrient reduction in cultures was measured at different initial substrate strengths. A small, pilot-scale photobioreactor (PBR) was used to verify lab-scale results. Similar growth conditions supported growth of both Selenastrum and bacteria. CO2 feed enhanced the production of biomass and lipids in PBR (2.4 g L−1 and 17% DW) compared to lab-scale (0.1–1.6 g L−1 and 4.0–6.5% DW) experiments. Also prolonged cultivation time increased lipid content in PBR. At both scales, NH4-N with an initial concentration of ca. 40 mg L−1 was completely removed from the biowaste leachate. In lab-scale, maximal COD reduction was over 2000 mg L−1, indicating mixotrophic growth of Selenastrum. Co-cultures are efficient in composting leachate liquid treatment, and conversion of waste to biomass is a promising approach to improve the bioeconomy of composting plants
Socioeconomic Inequalities in Mortality Rates in Old Age in the World Health Organization Europe Region
Socioeconomic adversity is among the foremost fundamental causes of human suffering, and this is no less true in old age. Recent reports on socioeconomic inequalities in mortality rate in old age suggest that a low socioeconomic position continues to increase the risk of death even among the oldest old. We aimed to examine the evidence for socioeconomic mortality rate inequalities in old age, including information about associations with various indicators of socioeconomic position and for various geographic locations within the World Health Organization Region for Europe. The articles included in this review leave no doubt that inequalities in mortality rate by socioeconomic position persist into the oldest ages for both men and women in all countries for which information is available, although the relative risk measures observed were rarely higher than 2.00. Still, the available evidence base is heavily biased geographically, inasmuch as it is based largely on national studies from Nordic and Western European countries and local studies from urban areas in Southern Europe. This bias will hamper the design of European-wide policies to reduce inequalities in mortality rate. We call for a continuous update of the empiric evidence on socioeconomic inequalities in mortality rate
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