Internal Migration and Regional Population Dynamics in Europe: United Kingdom Case Study

This case study examines recent population change patterns and internal migration activity in the United Kingdom. A wealth of knowledge about population dynamics in Britain is revealed. The spatial patterns of population change and net migration are intricate mosaics of gains and losses. Gains and losses in population were principally determined by net internal migration. The decade long population change patterns and one year long migration patterns were in close agreement. This was surprising in view of temporal instability in population change and migration patterns. The dominant spatial pattern was one of deconcentration from the cores of city regions to hinterlands for both the largest metropolises and also their subsidiary partner cities. There were also signs of loss in population and migrants in declining resource regions(former mining areas, fishing ports) and gains in new resource frontiers - particularly in northeast Scotland reflecting the vigorous development of onshore facilities for the offshore oil and gas fields of the North Sea. The pattern of overall population and migrant redistribution was predominantly that of the middle labour force/family ages reinforced at much lower mobility levels but with sharper patterns of redistribution by the pre-retirement and retirement ages. People in the young adult ages in contrast redistributed to different destinations, showing a unique shift to the dense neighbourhoods of big cities. With respect to the urban system, there was significant redistribution both downward and outward. Downward redistribution meant shifts from large metropolitan cities to medium and small sized freestanding cities. Outward redistribution meant shifts to the outer commuting rings around cities, often deep into the countryside, This was not a return to the rural idyll, merely the expansion of the daily urban systems to cover most of lowland Britain. Strong preferences for low density living were revealed by shifts towards districts in Rural Areas and by net flows to low density wards and sectors. Similar strong shifts out of areas of above average into below average unemployment were detected, though both relationships with density and unemployment were either not present or weak for young adults. Some ambiguity was revealed in the fortunes of Inner London areas. Migration data from the 1991 Census showed intense outward movement. Downward population shifts were on a lesser scale because of the compensating effects of higher than average natural increase and high immigration. However, a re-analysis of 1991 population by ONS led to a substantial upward revision of London borough populations, and so places doubt on the size of outward shift of population through internal migration

Internal Migration and Regional Population Dynamics in Europe: German Case Study

Report prepared for the Council of Europe (Directorate of Social and Economic Affairs, Population and Migration Division) and for European Commission (Directorate General V, Employment, Industrial Relations and Social Affairs, Unit E1, Analysis and Research on the Social Situation) This paper reports on internal migration and regional population dynamics and to a lesser extend on international migration in Germany. It examines internal migration patterns and trends in two years, 1984, 1989 and 1993, and compares them. Germany has a particularly sophisticated population system with a large number of population categories behaving in a very different way. The indigenous population shows a pattern of urban deconcentration typical for affluent West-European countries, both in the forms of suburbanisation and counterurbanisation. All other groups of migrants, those coming from former East Germany, those of German origin coming from outside Germany (Aussiedler) and other international migrants, show a pattern of strong concentration in urban centres. As far as migrations from East to West Germany is concerned the pattern is changing, as the number of migrants declines rapidly. Also in East Germany itself there is a marked shift. The pattern of rapid concentration of population due mainly to rural to urban migration is moving, for the time being, to weak and fragmented deconcentration. This process will speed up with the economic development of Eastern Länder. Medium density areas gain people, high and low density areas lose people. The relationship between net migration on the one hand and population density on the other was strongly negative for low density areas and for the less populated areas. The gainers were areas with a medium density of population. The age of migrants has a profound impact on their behaviour. There are important variations in redistribution of population by life course stage. The dominant urban deconcentration was most characteristic of middle working and family ages and the pre-retirement and retirement ages. People in the young adult ages migrated in different directions, showing a unique shift to some dense neighbourhoods in big cities, those close to higher education institutions. Unemployment influences migration profoundly. People move between areas of differing unemployment in ways predicted by classical economic equilibrium theory, leaving areas of high unemployment and going to areas of lower unemployment. German population dynamics depends on three factors: natural increase (persistently negative), internal migration and international migration. International migration is the only factor which maintains the size of population and even allows for a moderate growth. There is no direct threat that the population inhabiting German territory, will decline in the near future, but this may happen to the German population

Spectral Properties of Blast Wave Models of Gamma-Ray Burst Sources

We calculate the spectrum of blast wave models of gamma-ray burst sources, for various assumptions about the magnetic field density and the relativistic particle acceleration efficiency. For a range of physically plausible models we find that the radiation efficiency is high, and leads to nonthermal spectra with breaks at various energies comparable to those observed in the gamma-ray range. Radiation is also predicted at other wavebands, in particular at X-ray, optical/UV and GeV/TeV energies. We discuss the spectra as a function of duration for three basic types of models, and for cosmological, halo and galactic disk distances. We also evaluate the gamma-ray fluences and the spectral characteristics for a range of external densities. Impulsive burst models at cosmological distances can satisfy the conventional X-ray paucity constraint S_x/S_\gamma \siml few percent over a wide range of durations, but galactic models can do so only for bursts shorter than a few seconds, unless additional assumptions are made. The emissivity is generally larger for bursts in a denser external environment, with the efficiency increasing up to the point where all the energy input is radiated away.Comment: 24 pages of Tex, plus 17 figures uuencoded tar-compressed postscript file

Crystallographic Analyses of Ion Channels: Lessons and Challenges

Membrane proteins fascinate at many levels, from their central functional roles in transport, energy transduction, and signal transduction processes to structural questions concerning how they fold and operate in the exotic environments of the membrane bilayer and the water-bilayer interface and to methodological issues associated with studying membrane proteins either in situ or extracted from the membrane. This interplay is beautifully exemplified by ion channels, a collection of integral membrane proteins that mediate the transmembrane passage of ions down their electrochemical potential gradient (for general reviews, see Refs. 1 and 2). Ion channels are key elements of signaling and sensing pathways, including nerve cell conduction, hormone response, and mechanosensation. The characteristic properties of ion channels reflect their conductance, ion selectivity, and gating. Ion channels are often specific for a particular type of ion (such as potassium or chloride) or a class of ions (such as anions) and are typically regulated by conformational switching of the protein structure between "open" and "closed" states. This conformational switching may be gated in response to changes in membrane potential, ligand binding, or application of mechanical forces. Detailed functional characterizations of channels and their gating mechanisms have been achieved, reflecting exquisite methodological advances such as patch clamp methods that can monitor the activities of individual channels (3). Until recently, corresponding information about the three-dimensional structures of channels was not available, reflecting difficulties in obtaining sufficient quantities of membrane proteins for crystallization trials. Happily, this situation has started to change with the structure determinations of the Streptomyces lividans K+ channel (KcsA (4)) and the Mycobacterium tuberculosis mechanosensitive channel (MscL (5)). A variety of reviews (6-12) have appeared recently that discuss functional implications of these channel structures. This review discusses these developments from a complementary perspective, by considering the implications of these structures from within the larger framework of membrane protein structure and function. Because of space restrictions, this review necessarily emphasizes membrane proteins that are composed primarily of alpha-helical bundles, such as KcsA and MscL, rather than beta-barrel proteins, such as porins, typically found in bacterial outer membranes

Internal Migration and Regional Population Dynamics in Europe: Norway Case Study

This paper reports on internal migration and regional population dynamics in Norway. It examines internal migration patterns and trends in two years, 1984 and 1994, and compares them. Norway's population maintains relatively high population growth by European standards, fuelled by continuing natural increase and net migration from outside the country. About half of Norway's municipalities lost population in aggregate over the 1984 to 1994. These municipalities are concentrated in the Centre-North and interior of southern Norway. There is evidence that communities with the lowest densities and least centrality are losing population through internal migration. Although the direction of migration is towards denser and more central places, this is a product mainly of the migration of young people when the migration streams are broken down by age, the resulting tales show that the largest urban areas are experiencing net losses from middle age and upwards. There is little direct evidence of net positive migration flows to rural remote areas for the population as a whole. Migration flows out of the Oslo region are to other municipalities within commuting range. This deconcentration should therefore be identified as extended suburanisation rather than counter-urbanisation. Throughout the current report the role of life course stage in influencing the direction of migration has been stressed. Most often the overall pattern of population shifts conceal very different flow structures for family migrants, young adults, older workers, retirees and the elderly. In this respect internal migration dynamics in Norway strongly resemble those in other West European countries. Economic factors have an important influence on migration patterns. Municipalities with an economic concentration in service industries attract internal migrants while those specialised in primary industry suffer migration outflows consequent on the decline of or productivity improvements in their economic activities. There is a strong gradient of increasing net outflows with increasing levels of unemployment

Internal Migration and Regional Population Dynamics in Europe: France Case Study

The paper examines the patterns of internal migration and population change in France over the recent decades at departément and commune scales. Regional population change is controlled by both natural increase and internal migration. There are two differing patterns of natural increase: north and east France has higher natural increase and south and east has lower. The geographic pattern of internal migration has changed substantially over the last 50 years, most dramatically in the Île-de-France, which showed the highest gains between 1954 and 1962 but the highest losses between 1975 and 1982. Urban growth, which was strong in the 1950s and 1960s, reversed in the 1970s favouring small towns but recovered slightly in the last 20 years. Migration gains and losses show a quite complicated pattern of depopulation of city centres combined with slow suburbanisation and advanced periurbanisation. Periurbanisation is evident in Paris region and in nearly all large urban agglomerations. Most other cities show suburbanisation or periurbanisation at various stages of development. Out-migration shows a clear division of the country into a northern part with higher rates, and a central and southern part of the country with lower out-migration. This simple pattern is modified by higher out-migration from some cities such as Lyon or Clermont-Ferrand and from isolated rural communes scattered all over the country. Out-migration also has a regional dimension: there are shifts towards more attractive areas, in particular Alpine region and Mediterranean and Atlantic coasts. Analysis of migration between size bands of rural and urban units shows a significant deconcentration process, and a similar pattern characterises migration between population density bands. The general movement is down the urban/density band hierarchy, from higher to lower urban/density bands. Deep rural areas are not attractive and excluded from the process of counterurbanisation. In addition, unemployment was found to have a strong and very efficient impact on migration behaviour. Analysis for 1990-1999 leads to slight modification of this picture: a slow recovery of central parts of the largest urban agglomerations and less differentiated patterns than in the 1980s. Deconcentration of the French population continues but is less powerful

Optimal solvers for PDE-Constrained Optimization

Optimization problems with constraints which require the solution of a partial differential equation arise widely in many areas of the sciences and engineering, in particular in problems of design. The solution of such PDE-constrained optimization problems is usually a major computational task. Here we consider simple problems of this type: distributed control problems in which the 2- and 3-dimensional Poisson problem is the PDE. The large dimensional linear systems which result from discretization and which need to be solved are of saddle-point type. We introduce two optimal preconditioners for these systems which lead to convergence of symmetric Krylov subspace iterative methods in a number of iterations which does not increase with the dimension of the discrete problem. These preconditioners are block structured and involve standard multigrid cycles. The optimality of the preconditioned iterative solver is proved theoretically and verified computationally in several test cases. The theoretical proof indicates that these approaches may have much broader applicability for other partial differential equations

Internal Migration and Regional Population Dynamics in Europe: Denmark Case Study

This report analyses the patterns of internal migration and population change across the communes of Denmark as part of a multi-country study of regional population dynamics in Europe, comparing the 1980s and 1990s. Section 2 of the report reviews the recent history of internal migration and regional/local population change in Denmark. Section 3 documents data sources and structure. Section 4 provides a detailed cartographic analysis of the patterns of in-migration, out-migration and net-migration at commune level for 1985 and 1998 (the years selected for study), while section 5 reviews population change between 1985 and 1998. Overall net migration shifts have decreased between the two years. The spatial pattern combines losses from peripheral regions (western Jutland, Bornholm) and Copehagen suburbs with gains to commuting belts centred on Copenhagen and the other large towns. As many other high income European countries, there is a profound contrast between the migration behaviour of young people and other adults (families, older workers and the retired). Young people move strongly towards the centre of the capital region and other large towns, while the other groups deconcentrate. Section 6 analyses the relationships between net migration/population change and the settlement system, to calibrate more precisely the patterns observed on the maps, while sections 7 and 8 look at the relationships between internal migration and economic/functional classifications of the communes. The former relationships are stronger than the latter, but are not as well clearly structured with respect to the urban hierarchy or population density as in many other countries studied. Denmark has reached a system state beyond simple counterurbanisation to be characterised by periurbanisation in the Copenhagen region, reurbanisation in Copenhagen itself and moderate outflows from rural regions