Relational Foundations For Functorial Data Migration

We study the data transformation capabilities associated with schemas that are presented by directed multi-graphs and path equations. Unlike most approaches which treat graph-based schemas as abbreviations for relational schemas, we treat graph-based schemas as categories. A schema $S$ is a finitely-presented category, and the collection of all $S$-instances forms a category, $S$-inst. A functor $F$ between schemas $S$ and $T$, which can be generated from a visual mapping between graphs, induces three adjoint data migration functors, $\Sigma_F:S$-inst$\to T$-inst, $\Pi_F: S$-inst $\to T$-inst, and $\Delta_F:T$-inst $\to S$-inst. We present an algebraic query language FQL based on these functors, prove that FQL is closed under composition, prove that FQL can be implemented with the select-project-product-union relational algebra (SPCU) extended with a key-generation operation, and prove that SPCU can be implemented with FQL

An Age-Period-Cohort Database of Inter-Regional Migration in Australia and Britain, 1976-96

Report prepared as part of a collaborative project on "Migration Trends in Australia and Britain: Levels and Trends in an Age-Period-Cohort Framework" funded by the Economic and Social Research Council and the Australian Research Council. This paper describes the way in which parallel databases of inter-regional migration flows for Australia and Britain, classified by five year ages and birth cohorts for four five year periods between 1976 and 1996. The data processing involves estimation of migration data for comparable spatial units, the reduction of the number of those units to a reduced set for ease of analysis, the extraction of migration data from official data files supplied by the Australian Bureau of Statistics and the Office for National Statistics, and the filling of gaps in these files through iterative proportional fitting for some of the British data. The final stage in preparation of the migration databases was to estimate the numbers of transitions (Australia) or movements (Britain) for age-period-cohort spaces. In principle, this last estimation involves a fairly simple interpolation or aggregation of age-time classified migration data, but in practice a great deal of detailed attention is required. A final section specifies the populations at risk to be used for each age-period-cohort observation plan to compute migration intensities

A forecast of international migration flows into EU countries until 2050

The subject of this paper is international migration into EU countries. The research objective is a quantitative estimation of the volume of international migration flows into European countries and their close neighbors until 2050. The forecast of international migration flows is based on the author’s own model of global international migration. The model is based on a synergetic approach and assumptions that the level of migration is determined first of all by the number of existing migrants from that country. The data used for the forecast is UN data on migration flows in 1990-2015, and the UN’s predictions regarding changes in population between now and 2050. The forecast is based on the medium scenario of demographic development offered by the UN. Countries with a current population of more than 5 million are taken into consideration as potential sources of immigration. The predicted values of the total number of international migration flows to each of the EU and neighboring countries for each five-year period until 2050 are determined. The predicted migration flows from EU countries are also determined. It is concluded that the forecasts allow us to claim that the problem of migration will con­tinue for EU countries. However, the essence of this problem is not the prevention of excess migration, but attracting migrants to the countries of the ‘second Europe.

An end-to-end software solution for the analysis of high-throughput single-cell migration data

The systematic study of single-cell migration requires the availability of software for assisting data inspection, quality control and analysis. This is especially important for high-throughput experiments, where multiple biological conditions are tested in parallel. Although the field of cell migration can count on different computational tools for cell segmentation and tracking, downstream data visualization, parameter extraction and statistical analysis are still left to the user and are currently not possible within a single tool. This article presents a completely new module for the open-source, cross-platform CellMissy software for cell migration data management. This module is the first tool to focus specifically on single-cell migration data downstream of image processing. It allows fast comparison across all tested conditions, providing automated data visualization, assisted data filtering and quality control, extraction of various commonly used cell migration parameters, and non-parametric statistical analysis. Importantly, the module enables parameters computation both at the trajectory-and at the step-level. Moreover, this single-cell analysis module is complemented by a new data import module that accommodates multiwell plate data obtained from high-throughput experiments, and is easily extensible through a plugin architecture. In conclusion, the end-to-end software solution presented here tackles a key bioinformatics challenge in the cell migration field, assisting researchers in their highthroughput data processing

Does relative deprivation induce migration?: evidence from Sub-Saharan Africa

This analysis revisits the decades-old relative deprivation theory of migration. In contrast to the traditional view that migration is driven by absolute income maximization, we test whether relative deprivation induces migration in the context of sub-Saharan Africa. Taking advantage of the internationally comparable longitudinal data from integrated household and agriculture surveys from Tanzania, Ethiopia, Malawi, Nigeria, and Uganda, we use panel fixed effects to estimate the effects of relative deprivation on migration decisions. Using per capita consumption expenditure and multidimensional wealth index as well-being measures, we find that a household’s migration decision is based not only on its absolute well-being level but also on the relative position of the household in the well-being distribution of the community in which it resides. We also discover that the effect of relative deprivation on migration is amplified in rural, agricultural, and male-headed households. Results are robust to alternative specifications including the use of Hausman Taylor Instrumental Variable (HTIV) estimator and pooled data across the five countries. Results confirm that the “migration-relative deprivation” relationship also holds in the context of sub-Saharan Africa. We argue that policies designed to check rural–urban migration through rural transformation and poverty reduction programs should use caution because such programs can increase economic inequality, which further increases migration flow

Internal Migration. Challenges and Perspectives for the Research Infrastructure

Research on internal migration covers a wide range of issues with regard to the reasons, distance and direction of moves as well as the process of decision-making. Given the rich field of relevant research objectives and the substantial developments in migration theory it is apparent that the availability of a broad set of data including detailed information on various aspects of life is one of the key factors for ongoing progress in the analysis of internal migration development. Available official aggregated data are useful for descriptive structural analyses. But they are very limited in explaining causal relations. The same holds for cross-sectional data. Some of the described longitudinal data sets consist of retrospective collected event history data that are not suitable for collecting essential information about attitudes and psychological states of the respondents over time. Several prospective longitudinal survey data do not represent essential aspects of internal migration. Data should at least include information on the place of residence (on the smallest possible spatial level), typologies about the characteristics of the place of residence, change of residence, reasons of a move, intentions to move, the dwelling and the neighbourhood as well as on commuting.internal migration, regional migration, migration theory, official data, cross-sectional data, longitudinal data.

Fuel Costs, Migration, and Community Viability

ISER researchers compiled and reviewed existing studies and data sources relating to the economic and social viability of remote rural Alaska communities. We particularly looked for possible linkages between high fuel costs and migration. Our review indicates the following: (1) migration from smaller places toward larger places is an ongoing phenomenon that is more noticeable when birth rates drop; (2) there is no systematic empirical evidence that fuel prices, by themselves, have been a definitive cause of migration; (3) the pursuit of economic and educational opportunities appears to be a predominant cause of migration; (4) however, currently available survey data are not sufficient to definitively determine other reasons for migration, which could include concerns about public safety and/or alcohol abuse; 5) most of the survey data pre-date the latest rapid increase (2006-2008) in fuel prices. We suggest several ways that better data could be collected on community viability and the reasons for migration.First Alaskans Institute. Alaska Native Policy Center.Introduction / Methods / Findings / Significant data collection opportunities / Conclusions / References / Data Sources Use