98024 research outputs found
Sort by
The amendment value of pulp and paper mill sludges in Finnish coarse-textured soil
Get PDFAs a source of exogenous organic matter, pulp and/or paper mill sludges (PPMS) may have beneficial effects on crop productivity and soil chemical and physical properties. This study's aim was to assess the impacts of two different PPMS materials on crop yields, the quality of percolation water, and soil chemical and hydraulic properties in a three-year field experiment on a silt loam soil in East Central Finland. Fresh (FPMS) and lime-stabilized (LPMS) sludges were applied once at rates of 21–28 fresh-Mg ha−1 in the spring prior to the sowing of grass ley under barley as a cover crop and incorporated into the upper 7 cm soil layer. Supplemental nitrogen (N) was applied at levels of 40 and 80 kg ha−1. A decrease of barley grain yield due to N immobilization was observed at the N level 40 kg ha−1, but the standard N application rate (80 kg ha−1) connected with a moderate C:N ratio (FPMS 27:1, LPMS 24:1) was adequate to avoid significant yield losses. In the second and third year following the PPMS applications, there was a tendency for positive residual effects on the total dry matter yield of grass ley, which could be attributed to slow mineralization of sludge-N. The application of LPMS increased the pH in surface soil by 0.5–0.7-units and Ca concentration by 240–660 mg L−1 of soil relative to the non-amended control over the study period. In the year of PPMS applications, the amendments produced a significant increase (about 2.0 g kg−1) in the total carbon (C) concentrations in the uppermost 10 cm soil layer relative to the non-amended soil. During the following years, the change in soil C was no longer measurable, indicating relatively fast decomposition of sludge-C. Saturated hydraulic conductivity tended to be 1.4 to 2.3 times higher in the PPMS-treated soils than in the non-amended soil. Except for the decline in readily plant-available water, the other common water retention parameters were not significantly affected by the PPMS amendments. There were significant positive treatment effects on the amount of water retained between −13 and − 316 kPa matric potentials, suggesting an increase in medium-sized pores contributing to water storage in the soil. To maintain or enhance the beneficial direct and indirect effects of PPMS on crop yields and soil physico-chemical properties, repeated applications of PPMS are required, possibly combined with the use of organic fertilizers, especially during grass ley years.202
Associations Between Biodiversity, Forest Characteristics, Distance to Blue Space and Accelerometer-Measured Physical Activity - Northern Finland Birth Cohort 1966 Study
Get PDFWe studied how the quantity and quality of residential green spaces and distance to different types of blue spaces are associated with the accelerometer-measured physical activity (PA) among adults with different levels of total daily PA. The associations of the participants’ socio-demographic and personal characteristics and environmental features with light PA (LPA) and moderate-to-vigorous PA (MVPA) were analyzed using linear mixed models (n = 5470). The results indicated that greater residential forest area was associated with higher LPA among those with high level of total daily PA and with less MVPA among those with low level of total daily PA. Environments with high tree stand structure diversity or close to sea were associated with higher MVPA in high PA group. Varied natural environment can encourage leisure time activities in nearby nature, but individuals’ personal and socioeconomic variables seemed to be more strongly associated with LPA and MVPA than environmental characteristics.202
Sex-specific overdominance at the maturation vgll3 gene for reproductive fitness in wild Atlantic salmon
Get PDFLinking reproductive fitness with adaptive traits at the genomic level can shed light on the mechanisms that produce and maintain sex-specific selection. Here, we construct a multigenerational pedigree to investigate sex-specific selection on a maturation gene, vgll3, in a wild Atlantic salmon population. The vgll3 locus is responsible for ~40% of the variation in maturation (sea age at first reproduction). Genetic parentage analysis was conducted on 18,265 juveniles (parr) and 685 adults collected at the same spawning ground over eight consecutive years. A high proportion of females (26%) were iteroparous and reproduced two to four times in their lifetime. A smaller proportion of males (9%) spawned at least twice in their lifetime. Sex-specific patterns of reproductive fitness were related to vgll3 genotype. Females showed a pattern of overdominance where vgll3*EL genotypes had three-fold more total offspring than homozygous females. In contrast, males demonstrated that late-maturing vgll3*LL individuals had two-fold more offspring than either vgll3*EE or vgll3*EL males. Taken together, these data suggest that balancing selection in females contributes to the maintenance of variation at this locus via increased fitness of iteroparous vgll3*EL females. This study demonstrates the utility of multigenerational pedigrees for uncovering complex patterns of reproduction, sex-specific selection and the maintenance of genetic variation.202
A complex mechanism translating variation of a simple genetic architecture into alternative life histories
No full text202
Ennakoivan kasvinsuojelun keinoja
Get PDFEnnakoiva kasvinsuojelu pyrkii ehkäisemään kasvintuhoojaongelmien syntyä ja parantamaan viljelijän varautumista. Keinovalikoimaan kuuluvat tuholaiskantojen kehittymistä ehkäisevät ja luontaista torjuntaa ja tarkkailua vahvistavat viljelymenetelmät ja –toimet. Useat ennakoivan kasvinsuojelun toimet voivat auttaa vähentämään kasvinsuojeluaineiden käyttötarvetta ja tukevat myös viljelyvarmuutta ja maatalousluonnon monimuotoisuutta.202
The power of visualizing distributional differences: formal graphical n-sample tests
Get PDFClassical tests are available for the two-sample test of correspondence of distribution functions. From these, the Kolmogorov–Smirnov test provides also the graphical interpretation of the test results, in different forms. Here, we propose modifications of the Kolmogorov–Smirnov test with higher power. The proposed tests are based on the so-called global envelope test which allows for graphical interpretation, similarly as the Kolmogorov–Smirnov test. The tests are based on rank statistics and are suitable also for the comparison of n samples, with n ≥ 2. We compare the alternatives for the two-sample case through an extensive simulation study and discuss their interpretation. Finally, we apply the tests to real data. Specifically, we compare the height distributions between boys and girls at different ages, the sepal length distributions of different flower species, and distributions of standardized residuals from a time series model for different exchange courses using the proposed methodologies.202