214 research outputs found
Maaseudun pienyritysten strategiat, muutoskyvykkyys ja tuloksellisuus
vokMTT Taloustutkimus (MTTL
A Preliminary Study of Image Analysis for Parasite Detection on Honey Bees
International Conference Image Analysis and Recognition (ICIAR 2018, Póvoa de Varzim, Portugal
Biogeophysical impacts of peatland forestation on regional climate changes in Finland
Land cover changes can impact the climate by influencing the surface
energy and water balance. Naturally treeless or sparsely treed peatlands were extensively
drained to stimulate forest growth in Finland over the second half
of 20th century. The aim of this study is to investigate the
biogeophysical effects of peatland forestation on regional climate in
Finland. Two sets of 18-year climate simulations were done with the
regional climate model REMO by using land cover data based on
pre-drainage (1920s) and post-drainage (2000s) Finnish national
forest inventories.
In the most intensive peatland forestation area, located in the middle west of Finland, the results show a warming in April of up to 0.43 K in
monthly-averaged daily mean 2 m air temperature, whereas a slight
cooling from May to October of less than 0.1 K in general is found.
Consequently, snow clearance days over that area
are advanced up to 5 days in the mean of 15 years. No clear
signal is found for precipitation. Through analysing the simulated
temperature and energy balance terms, as well as snow depth over
five selected subregions, a positive feedback induced by peatland
forestation is found between decreased surface albedo and increased
surface air temperature in the snow-melting period. Our modelled
results show good qualitative agreements with the observational
data. In general, decreased surface albedo in the snow-melting period and
increased evapotranspiration in the growing period are the most
important biogeophysical aspects induced by peatland forestation
that cause changes in climate. The results from this study can be further integrally analysed with biogeochemical effects of peatland forestation
to provide background information for adapting future forest management to mitigate climate warming effects. Moreover, they
provide insights about the impacts of projected forestation of tundra at high latitudes due to climate change
Analysis of nucleation events in the European boundary layer using the regional aerosol-climate model REMO-HAM with a solar radiation-driven OH-proxy
This work describes improvements in the regional aerosol–climate model REMO-HAM in order to simulate more realistically the process of atmospheric new particle formation (NPF). A new scheme was implemented to simulate OH radical concentrations using a proxy approach based on observations and also accounting for the effects of clouds upon OH concentrations. Second, the nucleation rate calculation was modified to directly simulate the formation rates of 3 nm particles, which removes some unnecessary steps in the formation rate calculations used earlier in the model. Using the updated model version, NPF over Europe was simulated for the periods 2003–2004 and 2008–2009. The statistics of the simulated particle formation events were subsequently compared to observations from 13 ground-based measurement sites. The new model shows improved agreement with the observed NPF rates compared to former versions and can simulate the event statistics realistically for most parts of Europe
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Driving factors of aerosol properties over the foothills of central Himalayas based on 8.5 years continuous measurements
This study presents analysis of in situ measurements conducted over the period 2005–2014 in the Indian Himalayas to give a thorough overview of the factors and causes that drive aerosol properties. Aerosol extensive properties (namely, particle number concentration, scattering coefficient, equivalent black carbon, PM2.5, and PM10) have 1.5–2 times higher values in the early to late afternoon than during the night, and a strong seasonality. The interannual variability is ±20% for both PM2.5 and total particle number concentration. Analysis of the data shows statistically significant decreasing trends of −2.3 μg m−3 year−1 and −2.7 μg m−3 year−1 for PM2.5 and PM10, respectively, over the study period. The mountainous terrain site (Mukteshwar, MUK) is primarily under the influence of air from the plains. This is due to convective transport processes that are enhanced by local and mesoscale topography, leading to pronounced valley/mountain winds and consequently to atmospheric boundary layer air lifting from the plains below. The transport from plains is evident in seasonal‐diurnal patterns observed at MUK. The timing of the patterns corresponds with changes in turbulence and water vapor (q). According to our analysis, using these as proxies is a viable method for examining boundary layer influence in the absence of direct atmospheric boundary layer height measurements. Comparing the measurements with climate models shows that even regional climate models have problems capturing the orographic influence accurately at MUK, highlighting the importance of long‐term direct measurements at multiple points to understand aerosol behavior in mountainous areas
Root trenching: a useful tool to estimate autotrophic soil respiration? A case study in an Austrian mountain forest
We conducted a trenching experiment in a mountain forest in order to assess the contribution of theautotrophic respiration to total soil respiration and evaluate trenching as a technique to achieve it. We hypothesised that the trenching experiment would alter both microbial biomass and microbial community structure and that Wne roots (less than 2 mm diameter) would be decomposed within one growing season. Soil CO2 eZux was measured roughlybiweekly over two growing seasons. Root presence and morphology parameters, as well as the soil microbial community were measured prior to trenching, 5 and 15 months after trenching. The trenched plots emitted about 20 and 30% less CO2 than the control plots in the Wrst and secondgrowing season, respectively. Roots died in trenched plots, but root decay was slow. After 5 and 15 months, Wne root biomass was decreased by 9% (not statistically diferent)and 30%, (statistically diVerent) respectively. When wecorrected for the additional trenched-plot CO2 eZux due to Wne root decomposition, the autotrophic soil respiration rose to »26% of the total soil respiration for the Wrst growing season, and to »44% for the second growing season.Soil microbial biomass and community structure was not altered by the end of the second growing season. We conclude that trenching can give accurate estimates of the autotrophic and heterotrophic components of soil respiration, ifmethodological side eVects are accounted for, only
Impacts of emission reductions on aerosol radiative effects
The global aerosol-climate model ECHAM-HAMMOZ was used to investigate changes in the aerosol burden and aerosol radiative effects in the coming decades. Four different emissions scenarios were applied for 2030 (two of them applied also for 2020) and the results were compared against the reference year 2005. Two of the scenarios are based on current legislation reductions: one shows the maximum potential of reductions that can be achieved by technical measures, and the other is targeted to short-lived climate forcers (SLCFs). We have analyzed the results in terms of global means and additionally focused on eight subregions. Based on our results, aerosol burdens show an overall decreasing trend as they basically follow the changes in primary and precursor emissions. However, in some locations, such as India, the burdens could increase significantly. The declining emissions have an impact on the clear-sky direct aerosol effect (DRE), i.e. the cooling effect. The DRE could decrease globally 0.06-0.4 W m(-2) by 2030 with some regional increases, for example, over India (up to 0.84 W m(-2)). The global changes in the DRE depend on the scenario and are smallest in the targeted SLCF simulation. The aerosol indirect radiative effect could decline 0.25-0.82 W m(-2) by 2030. This decrease takes place mostly over the oceans, whereas the DRE changes are greatest over the continents. Our results show that targeted emission reduction measures can be a much better choice for the climate than overall high reductions globally. Our simulations also suggest that more than half of the near-future forcing change is due to the radiative effects associated with aerosol-cloud interactions.Peer reviewe
Stability and change in health behaviours as predictors for disability pension: a prospective cohort study of Swedish twins
<p>Abstract</p> <p>Background</p> <p>Stability or changes of health behaviours have not been studied in association with incidence of disability pension (DP). The aims were to (1) investigate if stability or changes in health behaviours predict DP due to musculoskeletal diagnosis (MSD), (2) to evaluate if an association exists for DP in general, and (3) after taking familial confounding into account.</p> <p>Methods</p> <p>The study sample was 16,713 like-sexed twin individuals born in Sweden between 1935-1958 (6195 complete twin pairs) who had participated in two surveys 25 years apart, were alive, and not pensioned at the time of the latest survey. Cox proportional hazards analysis was used to assess the associations (hazard ratios (HR) with 95% confidence intervals (CI)) between stability and change in health behaviours (physical activity, tobacco and alcohol use, body mass index (BMI)), and number of pain locations collected at two time points 25 years apart and the incidence of DP until 2008.</p> <p>Results</p> <p>During the follow-up, 1843 (11%) individuals were granted DP with 747 of these due to MSD. A higher proportion of women were granted DP than men. Increase in BMI and stable use of tobacco products were predictors for DP due to MSD (HR 1.21-1.48) and DP in general (HR 1.10-1.41). The stability in the frequency of physical activity and increased frequency of physical activity were protective factors for DP due to MSD only when accounting for familial confounding. However, the number of pain locations (stability, increase, or decrease) was the strongest predictor for future DP due to MSD (HR 3.69, CI 2.99-4.56) and DP in general (HR 2.15, CI 1.92-2.42). In discordant pair analysis, the HRs for pain were lower, indicating potential familial confounding.</p> <p>Conclusions</p> <p>Health behaviours in adulthood, including an increase in pain locations were associated with the incidence of DP. The association between physical activity and DP was especially related to adulthood choices or habits, i.e., the individual decision about frequency of exercising. Thus, it is important to e.g. increase public awareness of the potential beneficial effects of exercise throughout life to avoid permanent exclusion from the labour market for medical reasons.</p
Multivariate texture‐based segmentation of remotely sensed imagery for extraction of objects and their uncertainty
Modeling of synthesis and flow properties of propylene-diene copolymers
Copolymerization with nonconjugated dienes offers an attractive route for introducing long-chain branching in polypropylene. From a simplified set of rate equations for such copolymerization with a metallocene catalyst, we derive the probabilities of branch formation at different stages of the reaction in a semibatch reactor. Using these probabilities, we generate an ensemble of molecules via a Monte Carlo sampling. The knowledge of the branching topology and segment lengths allows us to compute the flow properties of the resins from computational rheology. We compare our model predictions with existing experimental data, namely the molar mass distribution and small amplitude oscillatory shear response, for a set of resins with varying diene content. The rheology data suggest that the entanglement time Ï.,e depends sensitively and in a well-defined fashion on the diene content
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