A statistical look at Modeen's forecast of the population of Finland in 1934

Gunnar Modeen made the first cohort-component forecast for Finland in 1934. This was a time when demographic transition was just over, but that fact could not have been known at the time. Would it have made any difference if Modeen had had the tools of modern time-series analysis available? We find that the essential question of how to deal with changing trends would have still been difficult. However; the modern tools would have given the forecast user a realistic indicator of the uncertainty of the forecast being made. This suggests that in developing countries that are undergoing transition now, more effort should he paid to the analysis of uncertainty of forecasting

On finite-temperature holographic QCD in the Veneziano limit

Holographic models in the T=0 universality class of QCD in the limit of large number N_c of colors and N_f massless fermion flavors, but constant ratio x_f=N_f/N_c, are analyzed at finite temperature. The models contain a 5-dimensional metric and two scalars, a dilaton sourcing TrF^2 and a tachyon dual to \bar qq. The phase structure on the T,x_f plane is computed and various 1st order, 2nd order transitions and crossovers with their chiral symmetry properties are identified. For each x_f, the temperature dependence of p/T^4 and the quark-antiquark -condensate is computed. In the simplest case, we find that for x_f up to the critical x_c\sim 4 there is a 1st order transition on which chiral symmetry is broken and the energy density jumps. In the conformal window x_c<x_f<11/2, there is only a continuous crossover between two conformal phases. When approaching x_c from below, x_f\to x_c, temperature scales approach zero as specified by Miransky scaling.Comment: 66 pages, 29 figure

A note on the use of anticipatory covariates in event history analysis

Anticipatory covariates are regressors whose values become known only after the value of the dependent variable has been ascertained. Hoem (1995) has given an informal discussion concerning the possible pitfalls in the use of such covariates in event history analysis. This paper complements Hoem’s findings by using simple linear regression as the framework. It turns out that complex patterns of bias may be introduced by the use of anticipatory covariates. In all cases it may not be possible to guarantee that the magnitude of the bias remains small. Therefore, extreme care is needed in interpreting results from studies that have relied on anticipatory covariates

Farm Deaths in North Karelia

This study examined the effect of farm size on the mortality and survival of EasternFinnish farms in the late 1990s. Three different dimensions of farm size (i.e. hectaresoperated, number of milk cows, and hectares of forest) were compared. Data wereextracted from administrative records and covered all 4,527 active farms in NorthKarelia from 1995 to 1998. Results did not support the disappearing middle sizehypothesis presented by Weiss (1999). Farm size distributions were not bimodal.No empirical evidence was found of a process of polarisation into two centres ofattraction. As a whole, the analysis provides some support for the conclusion thatthe size of forest holding as measured by hectares of forest owned by farm does nothave an independent effect on the likelihood of survival. Its contribution dependson the other variables in the model

Assumptions for long-term stochastic population forecasts in 18 European countries: Hypothèses de projections stochastiquesàlong terme des populations de 18 pays européens

The aim of the ‘Uncertain Population of Europe’(UPE) project was to compute long-term stochastic (probabilistic) population forecasts for 18 European countries. We developed a general methodology for constructing predictive distributions for fertility, mortality and migration. The assumptions underlying stochastic population forecasts can be assessed by analysing errors in past forecasts or model-based estimates of forecast errors, or by expert judgement. All three approaches have been used in the project. This article summarizes and discusses the results of the three approaches. It demonstrates how the—sometimes conflicting—results can be synthesized into a consistent set of assumptions about the expected levels and the uncertainty of total fertility rate, life expectancy at birth of men and women, and net migration for 18 European countries

Managing arbuscular mycorrhizal fungi for bioprotection: Mn toxicity

We investigated whether an intact extraradical mycelium (ERM) is more effective than other forms of propagule from indigenous arbuscular mycorrhizal fungi (AMF) in providing protection against stress to a host plant. The response of wheat (Triticum aestivum L.) to Mn toxicity was studied in a two-phase greenhouse experiment. In Phase 1, four Mn tolerant species from the natural vegetation, ranging from strongly mycotrophic to non- or weakly mycotrophic, were grown to develop different amounts of ERM. Wheat was then planted (Phase 2) with the ERM fragmented by sieving (Disturbed Treatment) or kept intact with no prior soil disturbance (Undisturbed Treatment). The growth of wheat was doubled by earlier and faster mycorrhizal colonization (AC) in the presence of an intact ERM at planting. There was a positive correlation between plant growth and the reduction of Mn and enhancement of P and S uptake into shoots. However, the growth of plants in undisturbed soil was significantly affected by the ERM developer species, which was not explained by differences in AC. Colonization starting from an intact ERM greatly enhanced the potential of AMF for protection against Mn toxicity. However, the degree of protection depended on the plant previously grown to develop the ERM, suggesting that there may be functional diversity within the ERM developed by mycotrophic plants of the natural vegetation

Contaminação por mercúrio em sedimento e moluscos da Bacia do rio Bento Gomes, MT.

Os níveis de mercúrio total detectados no sedimento e tecidos moles de moluscos gastrópodos provenientes da bacia hidrográfica do rio Bento Gomes, embora baixos, mostraram indícios de contaminação. De um total de 69 amostras de sedimento analisadas, 26% apresentaram níveis de mercúrio total variando de 0,01 a 0,25 µg.g-1 de mercúrio (peso úmido). Os níveis de mercúrio obtidos em 54 amostras dos moluscos Ampullaria scalaris; A. canaliculata e Marisa planogira evidenciaram que 39% estavam contaminadas com níveis variando de 0,02 a 1,6 µg.g-1 de peso úmido. Estes resultados indicam que o mercúrio utilizado na extração de ouro de aluvião está atingindo o ambiente aquático e contaminado o sedimento e os organismos bentônicos desta área do Pantanal.bitstream/item/37304/1/BP58.pd

Interaction between Arbuscular Mycorrhizal Fungi and rhizobia on the growth of subclover under Mn toxicity: The role of Extraradical Mycelium.

When Arbuscular Mycorrhizal (AM) colonization started from an intact extraradical mycelium (ERM) its bioprotective effect on subclover was enhanced in comparison with other sources of inoculum. The presence in the soil of an intact ERM, developed previously on mycotrophic plants tolerant to Mn toxicity, resulted in the earlier colonization of subclover, reduced Mn concentration in the roots, improved development and activity of root nodules, and enhanced N acquisition