8,118 research outputs found
Issues of Selection in Human Survivorship: A Theory of Mortality Change from the Mid-Eighteenth to the Early Twenty First Century
Is variation in empirical mortality across populations consistent with a hypothesis of selec-tion? To examine this proposition an extended frailty mortality model is put forward; incor-porating biological frailty; a common non-parametric hazard, joint for men and women, rep-resenting endogenous mortality in terms of degenerative aging (senescence); and environ-mental influence on survivorship. As the model is fitted to empirical cohort mortality exhibit-ing extreme variation, biological aging is identified up to a multiplicative factor. Mortality of elected cohorts born in Sweden, Denmark, and Iceland during the past 250 years and in Japan any ten years between 1950 and 1990 is approached appropriately by the model. Reduced natural selection may account for a substantial part of the empirical mortality change in the course of the demographic transition. Survivorship in the late nineteenth and the twentieth century ties selection to major medical advances and rapid recent mortality decline, probably with consequences for future health and survivorship.biodemography; congenital frailty; selection; heterogeneity; cohort mortality; stochastic micro-simulation; longevity
How Likely Is Factor Price Equalization?
The idea of treating factor price equalization as a situation, where the distribution of factors among countries is compatible with an equilibrium in an integrated world economy, has been refined to give the so-called lens condition for factor price equalization. In this paper, we show that the lens condition may be used to give estimates for the probability of factor price equalization when factors are distributed randomly among countries and, in addition, the techologies are sampled according to a given probability distribution. The estimates indicate that factor price equalization may occur less often than intuitively conceived.international trade; Factor Price Equalization; lens condition
Financial Intermediation, Moral Hazard, And Pareto Inferior Trade
We consider a simple model of international trade under uncertainty, where production takes time and is subject to uncertainty. The riskiness of production depends on the choices of the producers, not observable to the general public, and these choices are influenced by the availability and cost of credit. If investment is financed by a bond market, then a situation may arise where otherwise identical countries end up with different levels of interest and different choices of technique, which again implies differences in achieved level of welfare. Under suitable conditions on the parameters of the model, the market may not be able to supply credits to one of the countries. The introduction of financial intermediaries with the ability to control the debtors may change this situation in a direction which is welfare improving (in a suitable sense) by increasing expected output in the country with high interest rates, while opening up for new problems of asymmetric information with respect to the monitoring activity of the banksCapital Outflow, Financial Intermediaries, Moral Hazard
Rebalancing Unemployment Benefits in a Unionized Labour Market.
The basic trade union model is extended to allow for a more sophisticated unemployment benefit system consisting of two benefit levels, one for short-term and one for long-term unemployed, and a rule determining whether an unemployed is short- or long-term. The purpose of this extension is twofold; to get a more realistic analysis of the actual benefit systems in most countries, and to analyse alternative reforms to the traditional one of changing a uniform benefit level. Reforms that rebalance the benefit rates holding constant either expected utility of an unemployed, aggregate benefit expenditures, or aggregate utility of union members can reduce unemployment.
High damage potential of seed-borne spot blotch in organically grown spring barley in Denmark
Spot blotch of barley (Bipolaris sorokiniana, perfect state: Cochliobolus sativus) occurs wherever barley is grown but is normally not considered a major problem in Danish barley production. It is therefore not included in routine disease surveys or official variety testing in Denmark. However, recommended seed contamination thresholds are 30% for spring barley and 15% for winter barley. Several spring barley varieties were grown under organic (no seed dressing, mechanical weeding) and conventional (seed dressing with fungicides, herbicide application) production conditions at three sites in Denmark in 2003. The harvested seeds were analysed for contamination levels of seed-borne B. sorokiniana using a blotter method. The percentage of seeds contaminated with B. sorokiniana ranged from about 5 to 95 % and was highly depending on the site, production system and variety. Contamination levels of organically cultivated plots were about twice as high as those of plots receiving conventional treatments. The germinating ability of seeds was highly affected by the level of B. sorokiniana contamination and declined drastically at contamination levels above 60%. This effect appeared to differ among varieties. The 1000-grain weight was not affected by the level of spot blotch contamination of seeds. The results indicate that the importance of spot blotch may be underrated, especially in organic barley production and that the role of varietal resistance should be investigated. More results are expected from ongoing seed analyses
Analysis of trends in hydrochemical parameters in the Western Baltic in the 1980s
Trends in the hydrographic properties and nutrient concentrations of the Western Baltic from 1980 to 1990 are identified from national and HELCOM data (GESPA) and compared with those of the preceding decades. Found to be generally weak, these trends are analysed and discussed as integrated effects of the biological and chemical sink capacities of the ecosystem, natural effects (meteorological and hydrographic
changes and water exchange), and anthropogenic factors. Measurements in the Kiel Bight are used to study modifications of annual cycles due to climatic fluctuations. It is demonstrated that the Kiel Bight area is representative of a considerable part of the Baltic Sea. The generation of artificial trend signals is discussed as a consequence of non-matching scales of processes and sampling frequencies and of changes in annual cycles, and effects of non-random properties of the data used for statistical treatment.
The results of this discussion are used to evaluate the trends observed during the past
decades. The congruence of the observed nutrient trends in the Kiel Bight and the descriptive and prognostic results of the Wulff and Stigebrandt budget model for the Baltic Sea and some subareas are examined
Fahrtbericht "Poseidon"-Fahrt Nr. 88/3-88/4 [POS88/3-4], mittlere Ostsee - 2.6.-24.6.1982
Im Rahmen der Forschungsfahrt wurden wissenschaftliche Fragestellungen der Nährstoffchemie, der organischen Chemie, der Planktologie und der Mikrobiologie interdisziplinär und zum Teil in internationaler Zusammenarbeit mit schwedischen ("ARGOS", Planktol./Chem.) und estnischen ("AYU DAG", Phys.) Arbeitsgruppen bearbeitet.
Die internationale Zusammenarbeit betraf vor allem die synoptische Untersuchung kleinräumiger Veränderlichkeiten chemischer, physikalischer und planktologischer Parameter im Rahmen eines vom BMFT und der DFG geförderten Projektes. Die Pronennahme für die planktologischen, mirkobiologischen und z.T. auch für die org.
chemischen Untersuchungen orientierten sich an den Probennahmen dieses Programms, um zeitlich und räumlich interdisziplinär vergleichbare
Daten zu erhalten
Fahrtbericht F.S. "Poseidon" Nr. 75 (I/II) [POS75] vom 10. Juni bis 29. Juni 1981
Die 75. "Poseidon"-Fahrt in die Ostsee wurde als kombiniertes chemisch-physikalisches -Experiment durchgeführt. Teilnehmende Schiffe waren außer F.S. "Poseidon" F.S."Alkor" und R.V. "Ayu Dag" der Estnischen Akademie der Wissenschaften. Es wurden Untersuchungen
auf den Gebieten 1) Organische Substanzen im Meerwasser und in der Atmosphäre 2) Spurenmetalle im Meerwasser 3) Kleinräunige Variationen chemischer und physikalischer Parameter (koordinierte Messungen "Ayu Dag" und "Poseidon") durchgeführt
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