Use of wetlands, ponds and buffer zones in Finland

Main purpose of the CWs (constructed wetlands) for the treatment of runoff from agricultural areas is to reduce nutrient loading to surface waters and hence combat eutrophication. The most important single design parameter controlling retention effectiviness of a CW is its area in relation to the catchment area. Input concentrations, catchment properties(soil type!), hydraulic efficiency and CW soil properties also have a significant influence on the effectiviness

On the role of the environments and star formation for quasar activity

We investigate the host galaxy and environment properties of a sample of 400 low z (<0.5) quasars that were imaged in the SDSS Stripe82. We can detect and study the properties of the host galaxy for more than 75% of the data sample. We discover that quasar are mainly hosted in luminous galaxies of absolute magnitude M* -3 < M(R) < M* and that in the quasar environments the galaxy number density is comparable to that of inactive galaxies of similar luminosities. For these quasars we undertake also a study in u,g,r,i and z SDSS bands and again we discover that the mean colours of the quasar host galaxy it is not very different with respect to the values of the sample of inactive galaxies. For a subsample of low z sources the imaging study is complemented by spectroscopy of quasar hosts and of close companion galaxies. This study suggests that the supply and cause of the nuclear activity depends only weakly on the local environment of quasars. Contrary to past suggestions, for low redshift quasar there is a very modest connection between recent star formation and the nuclear activity.Comment: 10 pages, 4 figures, proceedings of the conference "QUASARS at all cosmic epochs", accepted for publication on Frontiers in Astronomy and Space Scienc

Oxygen abundances in low surface-brightness galaxies

Recent theories predict that some protogalaxies, in low-density environments of the field, are contracting and interacting so slowly that global star formation can be delayed until today. These systems should be gas rich and have low surface-brightness. Blue compact galaxies (BCG's) and other compact HII region galaxies currently experiencing a burst of star formation are good candidates of truly young galaxies (in the sense that global star formation recently has been initiated). If they really are young, they ought to have a recent phase when their brightness was much lower than in the bursting phase. No claims of observations of such proto-BCG's exist. Observations of galaxies in their juvenile phases would undoubtedly be of great interest, e.g. the determination of the primordial helium abundance would improve. A proper place to search for young nearby galaxies could be among blue low surface-brightness galaxies (BLSBG's) in the local field. The study of low surface-brightness galaxies (LSBG's) as a group began relatively recently. They are galaxies with extraordinary properties both as individuals and as a group. A few years ago we started an optical study of a sample of BLSBG's selected from the ESO/Uppsala catalogue. Results of spectroscopic observations obtained on a subsample - 8 galaxies - of our selection are reported. The HII region oxygen chemical abundances and its relation to the blue absolute magnitude and surface-brightness is investigated

WARFARE AND WELFARE? Understanding 19th and 20th Century Central Government Spending

This paper evaluates theories aiming to explain the size and growth of government spending, develops a framework inclusive of the so-called guns vs. butter tradeoff effect, and offers insights especially for the period 1870-1938. There were differences between the excessive and responsive government explanations, and between the long-run and short-run explanations, as well as cross-section and time series approaches. Here central government spending, conditioned by the regime characteristics, is proposed to be analyzed on the basis of the demand characteristics of military spending and social spending, their interaction, public debt constraints, as well as institutional constraints and other environmental variables.