This essay reflects on the conceptual underpinnings of research on ‘shrinking cities' over the last decade. It criticizes the definition of shrinkage in terms of urban population losses and argues ...that the state‐of‐the art research on ‘shrinking cities' suffers from a misleading conceptualization of shrinkage which forces essentially different urban constellations into a universal model of ‘shrinkage'. Four problems of this procrustean bed are discussed in detail: methodological pitfalls of threshold definitions of urban shrinkage; empirical contradictions; an absence of attention to scalar interrelations; and insufficient understanding of cities as historical processes. The essay ends with suggestions for a widened conceptualization of shrinkage and a new research agenda.
Recent discussions of urban governance have emphasized a trend towards the ‘entrepreneurialization’ of local politics. This model has been intensively discussed and well documented. However, although ...this concept has been well tested in economically prosperous locations, less attention has been paid to the situation in marginalized regions characterized by a weak economy and a declining population. Taking eastern Germany as an example of a socio‐economic context marked by deindustrialization and population decline, the article discusses three main aspects of local governance arrangements under such conditions. First ‘coping with decline’ has become a more important issue in local politics than ‘entrepreneurial’ growth‐strategies. Second, successful public–private coalition‐building is severely complicated. Third, local politics are more dependent on resources from the national government than on private investment, lending greater significance to the national level and resulting in ‘grant coalitions’ rather than ‘growth coalitions’. The article focuses on these different experiences and discusses their implications for the analysis of urban governance.
Résumé
De récentes discussions sur la gouvernance urbaine ont mis en évidence une tendance ‘entrepreneuriale’ de la politique locale. Ce modèle a été largement analysé et documenté. Toutefois, même si ce concept a été mis à l'épreuve sur des sites d'économie prospère, on s'est moins intéresséà la situation dans des régions marginalisées caractérisées par une économie faible et une population en déclin. Prenant l'Allemagne de l'Est comme exemple de contexte socio‐économique marqué par la désindustrialisation et le déclin démographique, l'article y examine trois grands aspects des dispositifs de gouvernance locale. Premièrement, ‘gérer le déclin’ est devenu une priorité de la politique locale plus prégnante que les stratégies de croissance ‘entrepreneuriales’. Deuxièmement, les coalitions public‐privé performantes sont extrêmement difficiles à constituer. Troisièmement, la politique locale dépend davantage des ressources gouvernementales nationales que de l'investissement privé, ce qui confère une prédominance au niveau national et génère des ‘coalitions de subventionnement’ au lieu de ‘coalitions de croissance’. En s'intéressant à ces différentes expériences, l'article examine leurs implications dans l'analyse de la gouvernance urbaine.
Abstract
With the rapid increase of sequenced metazoan mitochondrial genomes, a detailed manual annotation is becoming more and more infeasible. While it is easy to identify the approximate location ...of protein-coding genes within mitogenomes, the peculiar processing of mitochondrial transcripts, however, makes the determination of precise gene boundaries a surprisingly difficult problem. We have analyzed the properties of annotated start and stop codon positions in detail, and use the inferred patterns to devise a new method for predicting gene boundaries in de novo annotations. Our method benefits from empirically observed prevalances of start/stop codons and gene lengths, and considers the dependence of these features on variations of genetic codes. Albeit not being perfect, our new approach yields a drastic improvement in the accuracy of gene boundaries and upgrades the mitochondrial genome annotation server MITOS to an even more sophisticated tool for fully automatic annotation of metazoan mitochondrial genomes.
In this article, we focus on ways in which ‘internal migration industries’ shape the housing location of refugees in cities. Based on empirical studies in Halle, Schwerin, Berlin, Stuttgart and ...Dresden, we bring two issues together. First, we show how a specific financialised accumulation model of renting out privatised public housing stock to disadvantaged parts of the population has emerged that increasingly targets migrant tenants. With the growing immigration of refugees to Germany since 2015, this model has intensified. Second, we discuss how access to housing is formed by informal agents. While housing is almost inaccessible for households on social welfare, the situation is even worse for refugees. This situation has given rise to a new ‘shadow economy’ for housing that offers services with dubious quality for excessive fees. Bringing these two issues together, we argue that housing provision to refugees has become a new business opportunity. This has given rise to a broad variety of ‘internal migration industries’ that provide the housing infrastructure, but also control access to housing. This not only results in new opportunities for profit extraction, but actively shapes new patterns of segregation and the concentration of refugees in particular types of disadvantaged neighbourhoods.
Conceptualizing Urban Shrinkage Haase, Annegret; Rink, Dieter; Grossmann, Katrin ...
Environment and planning. A,
07/2014, Letnik:
46, Številka:
7
Journal Article
Recenzirano
Odprti dostop
Since the second half of the 20th century, urban shrinkage has become a common pathway of transformation for many large cities across the globe. Although the appearance of shrinkage is fairly ...universal—typically manifested in dwindling population, emerging vacant spaces, and the underuse of existing urban infrastructure, ranging from schools and parks to water pipelines—its essence is hidden from view. Phenomena related to shrinkage have been discussed predominantly using terms such as decline, decay, blight, abandonment, disurbanization, urban crisis, and demographic change. Amongst others, these concepts were typically related to specific national contexts, installed in distinct explanatory frameworks, based around diverging normative accounts, ultimately leading to very different policy implications. Yet there is still a lack of conceptualization and integration of shrinkage into the wider theoretical debates in human geography, town and country planning, urban and regional studies, and social sciences at large. The problem here is not only to explain how shrinkage comes about, but also to study shrinkage as a process: simultaneously as a presupposition, a medium, and an outcome of continually changing social relationships. If we wish to understand shrinkage in a specific location, we need to integrate theoretical explanations with historical trajectories, as well as to combine these with a study of the specific impacts caused by shrinkage and to analyse the policy environment in which these processes take place. The authors apply an integrative model which maps the entire process across different contexts and independently of local or national specifics; it covers causes, impacts, responses, and feedback loops, and the interrelations between these aspects. The model does not ‘explain’ shrinkage in every case: instead, it builds a framework into which place-specific and time-specific explanations can be embedded. It is thus a heuristics that enables communication, if not comparison, across different contexts. With the help of this model, the authors hope to find a way in which shrinkage can be studied both in a conceptually rigorous and in an historically specific way. Instead of an invariant ‘process of shrinkage’, they portray a ‘pluralist world of shrinkages’.
Varieties of shrinkage in European cities Haase, Annegret; Bernt, Matthias; Großmann, Katrin ...
European urban and regional studies,
01/2016, Letnik:
23, Številka:
1
Journal Article
Recenzirano
The issue of urban shrinkage has become the new ‘normal’ across Europe: a large number of urban areas find themselves amongst the cities losing population. According to recent studies, almost 42 per ...cent of all large European cities are currently shrinking. In eastern Europe, shrinking cities have formed the overwhelming majority – here, three out of four cities report a decrease in population. Shrinkage has proved to be a very diverse and complex phenomenon. In our understanding, a considerable and constant loss of population by an urban area classifies it as a shrinking city. So, while the indicator of shrinkage used here is rather simple, the nature of the process and its causes and consequences for the affected urban areas are multifaceted and need to be explained and understood in further detail. Set against this background, the article presents, first, urban shrinkage as both spatially and temporally uneven. Second, this article shows that the causes of urban shrinkage are as varied as they are numerous. We explore the ‘pluralist world of urban shrinkage’ in the European Union and beyond. The article provides an original process model of urban shrinkage, bringing together its causes, impacts and dynamics, and setting them in the context of locally based urban trajectories. The main argument of this arrticle is that there is no ‘grand explanatory heuristics’ of shrinkage; a ‘one-size-fits-all’ explanatory approach to shrinkage cannot deliver. To progress and remain relevant, one ought to move away from outcome-orientated towards process-orientated research on urban shrinkage.
A wide range of scientific fields, such as forensics, anthropology, medicine, and molecular evolution, benefits from the analysis of mitogenomic data. With the development of new sequencing ...technologies, the amount of mitochondrial sequence data to be analyzed has increased exponentially over the last few years. The accurate annotation of mitochondrial DNA is a prerequisite for any mitogenomic comparative analysis. To sustain with the growth of the available mitochondrial sequence data, highly efficient automatic computational methods are, hence, needed. Automatic annotation methods are typically based on databases that contain information about already annotated (and often pre-curated) mitogenomes of different species. However, the existing approaches have several shortcomings: 1) they do not scale well with the size of the database; 2) they do not allow for a fast (and easy) update of the database; and 3) they can only be applied to a relatively small taxonomic subset of all species. Here, we present a novel approach that does not have any of these aforementioned shortcomings, (1), (2), and (3). The reference database of mitogenomes is represented as a richly annotated de Bruijn graph. To generate gene predictions for a new user-supplied mitogenome, the method utilizes a clustering routine that uses the mapping information of the provided sequence to this graph. The method is implemented in a software package called DeGeCI
(De
Bruijn graph
Ge
ne
C
luster
I
dentification). For a large set of mitogenomes, for which expert-curated annotations are available, DeGeCI generates gene predictions of high conformity. In a comparative evaluation with MITOS2, a state-of-the-art annotation tool for mitochondrial genomes, DeGeCI shows better database scalability while still matching MITOS2 in terms of result quality and providing a fully automated means to update the underlying database. Moreover, unlike MITOS2, DeGeCI can be run in parallel on several processors to make use of modern multi-processor systems.
Identifying the locations of gene breakpoints between species of different taxonomic groups can provide useful insights into the underlying evolutionary processes. Given the exact locations of their ...genes, the breakpoints can be computed without much effort. However, often, existing gene annotations are erroneous, or only nucleotide sequences are available. Especially in mitochondrial genomes, high variations in gene orders are usually accompanied by a high degree of sequence inconsistencies. This makes accurately locating breakpoints in mitogenomic nucleotide sequences a challenging task.
This contribution presents a novel method for detecting gene breakpoints in the nucleotide sequences of complete mitochondrial genomes, taking into account possible high substitution rates. The method is implemented in the software package DeBBI. DeBBI allows to analyze transposition- and inversion-based breakpoints independently and uses a parallel program design, allowing to make use of modern multi-processor systems. Extensive tests on synthetic data sets, covering a broad range of sequence dissimilarities and different numbers of introduced breakpoints, demonstrate DeBBI 's ability to produce accurate results. Case studies using species of various taxonomic groups further show DeBBI 's applicability to real-life data. While (some) multiple sequence alignment tools can also be used for the task at hand, we demonstrate that especially gene breaks between short, poorly conserved tRNA genes can be detected more frequently with the proposed approach.
The proposed method constructs a position-annotated de-Bruijn graph of the input sequences. Using a heuristic algorithm, this graph is searched for particular structures, called bulges, which may be associated with the breakpoint locations. Despite the large size of these structures, the algorithm only requires a small number of graph traversal steps.
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