4,054 research outputs found
Economic analysis of field afforestation and forest clearance for cultivation in Finland
Rational land use decisions of private landowners are analysed in the framework of Common Agricultural Policy and other public support schemes effective in Finland in 2003. Net present values are computed for a marginal hectare of a typical Finnish farm. Three alternative land uses are considered: traditional cultivation of oats (Avena sativa L.), cultivation of reed canary grass (Phalaris Arundinacea L.) for energy production, and production of Norway spruce (Picea abies [L.] Karst.) timber. Both arable land and forested land are considered as initial states. Experimental data from 38 afforested stands and distance-independent individual-tree stand growth model are used for computing discounted net returns from forestry. Statistics on market prices, average yields, prices and costs are used for obtaining estimates of land value under agricultural and energy production. Cultivation of energy grass gives clearly the highest economic outcome for arable land, but it has limited demand only in the neighbourhood of thermal power stations. Maintaining arable lands under traditional food production gives higher land value than afforestation. Without an option for agricultural use, public support makes afforestation investments profitable even for the least successfully established forest stands. However, possibilities to sell or to rent out retain arable lands under agricultural production, and explain poor success of the latest afforestation programme. Clearing additional forestland for agricultural production turns rational if clearing of the site is inexpensive, relative value growth of the existing timber stock is low, and future prospects of agricultural production are dependent on scale advantages.Common Agricultural Policy, energy grass, incentives, land use, Resource /Energy Economics and Policy,
Reliability of estimation of timber assortment distribution in National Forest Inventory of Finland.
Non-metric chaotic inflation
We consider inflation within the context of what is arguably the simplest
non-metric extension of Einstein gravity. There non-metricity is described by a
single graviscalar field with a non-minimal kinetic coupling to the inflaton
field , parameterized by a single parameter . We discuss the
implications of non-metricity for chaotic inflation and find that it
significantly alters the inflaton dynamics for field values , dramatically changing the qualitative behaviour in this regime.
For potentials with a positive slope non-metricity imposes an upper bound on
the possible number of e-folds. For chaotic inflation with a monomial
potential, the spectral index and the tensor-to-scalar ratio receive small
corrections dependent on the non-metricity parameter. We also argue that
significant post-inflationary non-metricity may be generated.Comment: 7 pages, 1 figur
Population development and the public sector economy in Finland
Väestöliitto has newly published a book dealing with the effects of current population trends on society and the life of the common people. The aim of Väestöliitto is to use this book to begin a discussion on population questions and to direct attention to the necessity for planning authorities and decision makers to take demographic aspects into consideration in their work. The book discusses the effects of population aging on the public economy, education, industry and commerce as well as on the economy of the municipalities. We are here reproducing an article concerning the effects of population aging on the public economy and social expenditures. In economic theory population trends are considered exogenous, or factors outside the economic models. The authors, both economists, examine the link between population development and economy, mainly the public economy. They also discuss possible ways to avoid unwanted economic development caused by population aging. We feel the article might also interest readers outside the Finnish borders
The ideal energy of classical lattice dynamics
We define, as local quantities, the least energy and momentum allowed by
quantum mechanics and special relativity for physical realizations of some
classical lattice dynamics. These definitions depend on local rates of
finite-state change. In two example dynamics, we see that these rates evolve
like classical mechanical energy and momentum.Comment: 12 pages, 4 figures, includes revised portion of arXiv:0805.335
Attention-Deficit/Hyperactivity Disorder in Offspring of Mothers With Inflammatory and Immune System Diseases
AbstractBackgroundPrenatal inflammatory mechanisms may play a role in the pathogenesis of psychiatric disorders and could be relevant for attention-deficit/hyperactivity disorder (ADHD). We investigated maternal chronic somatic diseases with immune components as possible risk factors for ADHD in offspring.MethodsWe performed a population-based nested case-control study by linking data from longitudinal Norwegian registers. We included all individuals born during the period 1967–2008 and alive at record linkage (2012). Individuals receiving ADHD medication during the years 2004–2012 were defined as patients with ADHD (N = 47,944), and all remaining individuals (N = 2,274,713) were defined as control subjects. The associations between maternal diseases and ADHD in offspring were analyzed using logistic regression models.ResultsThe following chronic diseases with immune components were related to ADHD in offspring: multiple sclerosis (adjusted odds ratio [OR] = 1.8; 95% confidence interval [CI] = 1.2–2.5), rheumatoid arthritis (adjusted OR = 1.7; 95% CI = 1.5–1.9), type 1 diabetes (adjusted OR = 1.6; 95% CI = 1.3–2.0), asthma (adjusted OR = 1.5; 95% CI = 1.4–1.6), and hypothyroidism (adjusted OR = 1.2; 95% CI = 1.1–1.4). In contrast, chronic hypertension and type 2 diabetes showed no significant associations. Estimates were almost unchanged with additional adjustment for parental ADHD, infant birth weight, and gestational age. Although point estimates for male and female offspring were different for some diseases (e.g., maternal asthma [adjusted OR = 1.7; 95% CI = 1.5–1.8 for female offspring and adjusted OR = 1.5; 95% CI = 1.4–1.6 for male offspring]), none of the associations differed significantly by offspring sex.ConclusionsSeveral maternal somatic diseases with immune components were found to increase the risk of ADHD in offspring. The associations could involve several causal pathways, including common genetic predisposition and environmental factors, and increased insight into the mechanisms behind these relationships could enhance our understanding of the etiology of ADHD
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