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71.
There is a frequent need in the environmental sciences to show the similarity of the results given by two analytical methods. This cannot, however, be done within the conventional 'there is a difference' statistical hypothesis setting of, among others, Student's t-test. We demonstrate here a more appropriate approach that originates from drug testing and that can be applied with standard statistical software. It is a challenging approach, as it requires quantification of the similarity limit. If no pre-determined value is given for similarity, a potential data-supported similarity limit can be explored from the data. The approach has numerous other potential application areas, e.g. parallelism of regression slopes, homogeneity of variances and lack of interaction. 相似文献
72.
Olli Dahl Risto Pöykiö Hannu Nurmesniemi 《Journal of Material Cycles and Waste Management》2008,10(1):87-92
In Finland, the new limit values for heavy metals in fertilizers used in agriculture and in forestry came into force in March
2007, and for materials used as earth construction agents, in June 2006. From the utilization point of view, it was notable
that the total heavy metal concentrations (Cd, Cu, Pb, Cr, Mo, Zn, As, Ni, Ba, and Hg) in fly ash from a coal-fired power
plant were lower than those limit values. The concentrations of the easily soluble elements Ca, Mg, Na, P, and Zn in the fly
ash were between 3.5 and 35 times higher than those found in the coarse mineral soils of Finland. Fly ash is a potential agent
for soil remediation and for improving soil fertility. If inorganic materials and by-products are utilized in earthworks,
the content of harmful compounds must be low and the harmful components must be tightly bound to the matrix. Therefore, a
five-stage sequential extraction procedure was used to evaluate the extractability of different elements in fly ash into the
following fractions: (1) the water-soluble fraction, (2) the exchangeable fraction (CH3COOH), (3) the easily reduced fraction (NH2OH-HCl), (4) the oxidizable fraction (H2O2 + CH3COONH4), and (5) the residual fraction (HF + HNO3 + HCl). 相似文献
73.
Alkaline phosphatase (ALP) activity was determined in 255 amniotic fluid samples collected by amniocentesis between 15 and 39 weeks of gestation. The samples were originally used for chromosomal analysis and/or alpha-fetoprotein measurements. The mean ALP activity in early amniotic fluid from pregnancies with fetal trisomy 18 and 21 syndromes was half of that found in the controls. Highly elevated ALP activity (over 10 times the median level) was found in 14 samples. Two of these pregnancies had normal outcome. Three samples were from pregnancies with intrauterine fetal death. Fetal disorders, including abdominal wall defect (four cases), Meckel's syndrome (two), hydrops fetalis syndrome (two) and genital anomaly (one), were observed in nine cases. Moderately elevated ALP activity (over three times the median) was found in 10 cases, including five pregnancies with a preterm labour shortly after the sample collection. The results indicate that elevated ALP activity in the third trimester amniotic fluid is often associated with fetal disorders. 相似文献
74.
Monique Liesenjohann Thilo Liesenjohann Lenka Trebaticka Marko Haapakoski Janne Sundell Hannu Ylönen Jana A. Eccard 《Behavioral ecology and sociobiology》2011,65(11):2079-2089
Indirect exploitative competition, direct interference and predation are important interactions affecting species coexistence.
These interaction types may overlap and vary with the season and life-history state of individuals. We studied effects of
competition and potential nest predation by common shrews (Sorex araneus) on lactating bank voles (Myodes glareolus) in two seasons. The species coexist and may interact aggressively. Additionally, shrews can prey on nestling voles. We studied
bank vole mothers’ spatial and temporal adaptations to shrew presence during summer and autumn. Further, we focused on fitness
costs, e.g. decreased offspring survival, which bank voles may experience in the presence of shrews. In summer, interference
with shrews decreased the voles’ home ranges and they spent more time outside the nest, but there were no effects on offspring
survival. In autumn, we found decreased offspring survival in enclosures with shrews, potentially due to nest predation by
shrews or by increased competition between species. Our results indicate a shift between interaction types depending on seasonal
constraints. In summer, voles and shrews seem to interact mainly by interference, whereas resource competition and/or nest
predation by shrews gain importance in autumn. Different food availability, changing environmental conditions and the energetic
constraints in voles and shrews later in the year may be the reasons for the varying combinations of interaction types and
their increasing effects on the inclusive fitness of bank voles. Our study provides evidence for the need of studies combining
life history with behavioural measurements and seasonal constraints. 相似文献
75.
Holmberg Maria Mulder Jan Posch Maximilian Starr Michael Forsius Martin Johansson Matti Bak Jesper Ilvesniemi Hannu Sverdrup Harald 《Water, Air, & Soil Pollution: Focus》2001,1(1-2):91-101
We reviewed the current methods for calculatingcritical loads of acidity for forest soils. The consequencesof four sets of assumptions concerning the soil modelstructure, parameter values and the critical loads criterionwere explored by comparing the values of the averageaccumulated exceedance (AAE) calculated for Finland withdeposition values for the year 1995. The AAE index is given inthe unit of deposition and is a measure of how far a region isfrom being protected in terms of fulfilling a certaincriterion, taking into account the size of the ecosystem areas.Using a critical limit for the molar ratio of theconcentrations of base cations to aluminium in soil solutiongave the lowest average accumulated exceedance. Assumingorgano-aluminium complexes and leaching of organic anions gaveAAE = 4 eq ha-1 a-1, which was close to the valueobtained with the standard approach used in Finland, assuminggibbsite equilibrium and no leaching of organic anions,yielding AAE = 5 eq ha-1 a-1. With a critical basesaturation limit, instead of the concentrations criterion, theAAE index was 17 eq ha-1 a-1. The highest averageaccumulated exceedance (AAE = 25 eq ha-1 a-1),corresponding to the lowest critical load, was obtained whenthe effects-based criterion (critical concentration or criticalbase saturation) was substituted with one restricting thedeterioration of the neutralizing capacity of the soil, ANC
le(crit) = 0. These tests illustrate the variabilityof the critical load values for acidity that can be introducedby changing the criterion or by varying the calculation method,without, however, representing the extreme values of criticalloads that could be derived. 相似文献