Swedish University of Agricultural Sciences

About: Swedish University of Agricultural Sciences is a education organization based out in Uppsala, Sweden. It is known for research contribution in the topics: Population & Soil water. The organization has 13510 authors who have published 35241 publications receiving 1414458 citations. The organization is also known as: Sveriges Lantbruksuniversitet & SLU.

Protozoan grazing of bacteria in soil-impact and importance.

Abstract: Interactions between bacteria and protozoa in soil were studied over 2-week periods in the field and in a pot experiment Under natural conditions the total biological activity was temporarily synchronized by a large rainfall, and in the laboratory by the addition of water to dried-out soil, with or without plants In the field, peaks in numbers and biomass of bacteria appeared after the rain, and a peak of naked amoebae quickly followed Of the three investigated groups-flagellates, ciliates, and amoebae-only populations of the latter were large enough and fluctuated in a way that indicated a role as bacterial regulators The bacterial increase was transient, and the amoebae alone were calculated to be able to cause 60% of the bacterial decrease The same development of bacteria and protozoa was observed in the pot experiment: in the presence of roots, amoebic numbers increased 20 times and became 5 times higher than in the unplanted soil In the planted pots, the amoebic increase was large enough to cause the whole bacterial decrease observed; but in the unplanted soil, consumption by the amoebae caused only one-third of the bacterial decrease

Fungicides: An overlooked pesticide class?

Abstract: Fungicides are indispensable to global food security and their use is forecasted to intensify. Fungicides can reach aquatic ecosystems and occur in surface water bodies in agricultural catchments throughout the entire growing season due to their frequent, prophylactic application. However, in comparison to herbicides and insecticides, the exposure to and effects of fungicides have received less attention. We provide an overview of the risk of fungicides to aquatic ecosystems covering fungicide exposure (i.e., environmental fate, exposure modeling, and mitigation measures) as well as direct and indirect effects of fungicides on microorganisms, macrophytes, invertebrates, and vertebrates. We show that fungicides occur widely in aquatic systems, that the accuracy of predicted environmental concentrations is debatable, and that fungicide exposure can be effectively mitigated. We additionally demonstrate that fungicides can be highly toxic to a broad range of organisms and can pose a risk to aquatic biota. Finally, we outline central research gaps that currently challenge our ability to predict fungicide exposure and effects, promising research avenues, and shortcomings of the current environmental risk assessment for fungicides.

Anti-double-stranded DNA antibodies and immunostimulatory plasmid DNA in combination mimic the endogenous IFN-alpha inducer in systemic lupus erythematosus.

Abstract: Anti-double-stranded DNA antibodies and immunostimulatory plasmid DNA in combination mimic the endogenous IFN-alpha inducer in systemic lupus erythematosus

Hydration of the calcium ion. An EXAFS, large-angle x-ray scattering, and molecular dynamics simulation study.

Abstract: The structure of the hydrated calcium(II) ion in aqueous solution has been studied by means of extended X-ray absorption fine structure spectroscopy (EXAFS), large-angle X-ray scattering (LAXS), and molecular dynamics (MD) methods. The EXAFS data displayed a broad and asymmetric distribution of the Ca−O bond distances with the centroid at 2.46(2) A. LAXS studies on four aqueous calcium halide solutions (1.5−2 mol dm-3) gave a mean Ca−O bond distance of 2.46(1) A. This is consistent with a hydration number of 8 determined from correlations between mean distances and coordination numbers from crystal structures. The LAXS studies showed a second coordination sphere with a mean Ca···OII distance of 4.58(5) A, and for the hydrated halide ions the distances Cl···O 3.25(1) A, Br···O 3.36(1) A, and I···O 3.61(1) A were obtained. Molecular dynamics simulations of CaCl2(aq) were performed using three different Ca2+−OH2 pair potentials. The potential from the GROMOS program gave results in agreement with experiments...

Welfare Evaluations in Contingent Valuation Experiments with Discrete Response Data: Comment

Abstract: In the case of private goods, individuals reveal their preferences in the market place. No similar market mechanism exists in the case of public goods. However, one obvious possibility is to ask people about their maximal willingness to pay for public goods or government expenditure (Johansson 1987, 1990, Miller). In some recent contingent market valuation studies people instead have been asked to accept or reject a specified amount of money for a change in the provision of a public good; different subsamples are confronted with different "bids." The resulting "yes" and "no" responses usually are analyzed by logit or probit techniques (e.g., Johansson and Kristrom). This raises the question of how to compute the average willingness to pay when only yes and no responses are available. This point was advanced by Hanemann in his seminal 1984 paper on welfare evaluations with discrete responses; see also Hanemann (1987). However, we believe a minor imperfection in Hanemann's presentation may confuse and mislead practitioners. Hanemann's approach assumes that negative bids cannot occur but at the same time gives the impression that it also applies to models that allow for negative bids. We also extend Hanemann's discussion of the choice of money measure in cost-benefit analysis.