Varieties of Independent Living: Older Women in the Netherlands, 1982

Everywhere older people sooner or later come to suffer disabilities that make independent living difficult. In the IIASA countries, the majority of these old people are unmarried women. When and if they give up living alone because of their disabilities, it is found in other studies that they tend to live with or receive help from their children, if they have any, particularly daughters. The Netherlands shows a variant that appears to be the effect of extensive government construction of residences for the aged. These are specially designed for old people, including ramps instead of stairs, refrigerators and other equipment made easy to use. The availability of such residences permits a large portion of the elderly women who are disabled in one way or another to continue to live independently. Correspondingly, in the Netherlands, disability is a much weaker determinant for living with children than in some other countries. Of those elderly women who do live with a child, the majority now live with unmarried sons. Since it is hard to visualize sons cooking and making beds for their aged mothers, we may suppose the mothers are continuing their traditional role -- i.e., looking after their sons as well as themselves. This indicates that elderly women who might otherwise be in need of care are now able to continue to live independently thanks to special arrangements coming from the government, while elderly women able to give care continue to do so. This paper is one in a series of country case studies dealing with the effects of kin patterns and health on the household composition of older women

Population Futures for Europe: An Analysis of Alternative Scenarios

Population projections using arbitrary assumptions are made by many agencies, national and international, and there is no obvious need for one more set. But what distinguishes the projections of this Working Paper is the extremely wide range of assumptions in regard to births, deaths and migration with which the authors experimented. Moreover, they give a more explicit rationale for their assumptions than is commonly presented. In effect the paper answers such questions as "What if we have a new baby boom, short but intense, comparable to that of the 1950s?" "What if mortality improves spectacularly, not only at the ages to which people have lived up to now, but far beyond those ages, say though discovery of a magic drug?" On the other hand they also ask "What happens if some vast epidemic, such as AIDS, ravages the population of Europe?" Its imaginative assumptions are unlikely to be fulfilled, but none of them is impossible. This new set of perspectives goes beyond the more conventional projections that are currently in print in displaying what may happen in the future

On the motifs distribution in random hierarchical networks

The distribution of motifs in random hierarchical networks defined by nonsymmetric random block--hierarchical adjacency matrices, is constructed for the first time. According to the classification of U. Alon et al of network superfamilies by their motifs distributions, our artificial directed random hierarchical networks falls into the superfamily of natural networks to which the class of neuron networks belongs. This is the first example of ``handmade'' networks with the motifs distribution as in a special class of natural networks of essential biological importance.Comment: 7 pages, 5 figure

Late stage, non-equilibrium dynamics in the dipolar Ising model

Magnetic domain structures are a fascinating area of study with interest deriving both from technological applications and fundamental scientific questions. The nature of the striped magnetic phases observed in ultra-thin films is one such intriguing system. The non-equilibrium dynamics of such systems as they evolve toward equilibrium has only recently become an area of interest and previous work on model systems showed evidence of complex, slow dynamics with glass-like properties as the stripes order mesoscopically. To aid in the characterization of the observed phases and the nature of the transitions observed in model systems we have developed an efficient method for identifying clusters or domains in the spin system, where the clusters are based on the stripe orientation. Thus we are able to track the growth and decay of such clusters of stripes in a Monte Carlo simulation and observe directly the nature of the slow dynamics. We have applied this method to consider the growth and decay of ordered domains after a quench from a saturated magnetic state to temperatures near and well below the critical temperature in the two dimensional dipolar Ising model. We discuss our method of identifying stripe domains or clusters of stripes within this model and present the results of our investigations.Comment: 17 pages, 12 figures, submitted to JMM

Een gebied in beweging Verwachte ontwikkelingsrichtingen van landbouwbedrijven in de Veenkoloniën

De landbouw in de Veenkoloniën kenmerkt zich door een grote afhankelijkheid van granen, zetmeelaardappelen en suikerbieten. De komende jaren zullen hectarepremies en prijsondersteuning voor deze gewassen vervangen worden door geheel of gedeeltelijk van de productie losgekoppelde bedrijfstoeslagen. In dit project is een methode ontwikkeld voor het inventariseren van ontwikkelingsrichtingen die agrarische ondernemers zullen kiezen en de gevolgen daarvan voor het gebied; de methode is in principe ook toe te passen op andere gebieden. Agriculture in 'De Veenkoloniën' is characterised by a high level of dependency on cereals, starch potatoes and sugar beets, for which crop and price subsidies will be replaced by partly or fully de-coupled direct payments. In the project, a method has been developed to list development directions that farmers will choose and the consequences for the area; the method can be applied to other areas as well

Impact of Matric Potential and Pore Size Distribution on Growth Dynamics of Filamentous and Non-Filamentous Soil Bacteria

The filamentous growth form is an important strategy for soil microbes to bridge air-filled pores in unsaturated soils. In particular, fungi perform better than bacteria in soils during drought, a property that has been ascribed to the hyphal growth form of fungi. However, it is unknown if, and to what extent, filamentous bacteria may also display similar advantages over non-filamentous bacteria in soils with low hydraulic connectivity. In addition to allowing for microbial interactions and competition across connected micro-sites, water films also facilitate the motility of non-filamentous bacteria. To examine these issues, we constructed and characterized a series of quartz sand microcosms differing in matric potential and pore size distribution and, consequently, in connection of micro-habitats via water films. Our sand microcosms were used to examine the individual and competitive responses of a filamentous bacterium (Streptomyces atratus) and a motile rod-shaped bacterium (Bacillus weihenstephanensis) to differences in pore sizes and matric potential. The Bacillus strain had an initial advantage in all sand microcosms, which could be attributed to its faster growth rate. At later stages of the incubation, Streptomyces became dominant in microcosms with low connectivity (coarse pores and dry conditions). These data, combined with information on bacterial motility (expansion potential) across a range of pore-size and moisture conditions, suggest that, like their much larger fungal counterparts, filamentous bacteria also use this growth form to facilitate growth and expansion under conditions of low hydraulic conductivity. The sand microcosm system developed and used in this study allowed for precise manipulation of hydraulic properties and pore size distribution, thereby providing a useful approach for future examinations of how these properties influence the composition, diversity and function of soil-borne microbial communities

Analysis and development of entrepreneurship in agriculture

Sustainable agriculture is an important issue in the Netherlands. A balance between People, Planet and Profit is necessary to create a sustainable agriculture. Entrepreneurial qualities are important for farmers to find this balance for his particular situation. Therefore, three research institutes of Wageningen UR have started a joint project to analyse and develop entrepreneurship in agriculture, being started in 2002 and ending in 2005. This project is linked to several existing farmers networks, in which farmers are facilitated through research to develop organic or integrated agriculture. Entrepreneurship of co-operating farmers was analysed through a questionnaire, resulting in an overview of strengths and weaknesses. Through this, topics were identified for improvement of specific entrepreneurial qualities through participatory work. The results showed a generally low score on farm management and strategic planning, relationship with personnel and personnel management, information seeking and finding, learning and networking, and personal characteristics. In 2003 five participatory projects were started. Farmers were invited to participate in these projects. The projects existed in two or three meetings and farmers had to do some homework in between. Various analysis and simulation tools were used. Farmers received a report, in which individual results were compared with the group average. In 2004, all projects will get a second round and a new project about ‘employership’ will be set up. Monitoring and evaluation is an important issue in this project, to improve both the content and the process of the participatory projects. The lessons learned can also be translated into a training for advisors or into an educational course. The questionnaire is a useful tool for analysis of entrepreneurship and will be transformed to an internet tool for farmers. The participatory approach seems to be a fruitful method to improve entrepreneurial qualities of farmers

Effect of a columnar defect on the shape of slow-combustion fronts

We report experimental results for the behavior of slow-combustion fronts in the presence of a columnar defect with excess or reduced driving, and compare them with those of mean-field theory. We also compare them with simulation results for an analogous problem of driven flow of particles with hard-core repulsion (ASEP) and a single defect bond with a different hopping probability. The difference in the shape of the front profiles for excess vs. reduced driving in the defect, clearly demonstrates the existence of a KPZ-type of nonlinear term in the effective evolution equation for the slow-combustion fronts. We also find that slow-combustion fronts display a faceted form for large enough excess driving, and that there is a corresponding increase then in the average front speed. This increase in the average front speed disappears at a non-zero excess driving in agreement with the simulated behavior of the ASEP model.Comment: 7 pages, 7 figure