- Effects of sulforaphane on neural stem cell proliferation and
- Authors: Zhenxian Han; Qian Xu, Changfu Li, Hong Zhao
Abstract: Sulforaphane (SFN) is a natural organosulfur compound with anti-oxidant and anti-inflammation properties. The objective of this study is to investigate the effect of SFN on the proliferation and differentiation of neural stem cells (NSC). NSCs were exposed to SFN at the concentrations ranging from 0.25 to 10 µM. Cell viability was evaluated with MTT assay and lactate dehydogenase (LDH) release assay. The proliferation of NSCs was evaluated with neurosphere formation assay and Ki-67 staining. The level of Tuj-1 was evaluated with immunostaining and Western blot to assess NSC neuronal differentiation. The expression of key proteins in the Wnt signaling pathway, including β-catenin and cyclin D1, in response to SFN treatment or the Wnt inhibitor, DKK-1, was determined by Western blotting. No significant cytotoxicity was seen for SFN on NSCs with SFN at concentrations of less than 10 µM. On the contrary, SFN of low concentrations stimulated cell proliferation and prominently increased neurosphere formation and NSC differentiation to neurons. SFN treatment upregulated Wnt signaling in the NSCs, whereas DKK-1 attenuated the effects of SFN. SFN is a drug to promote NSC proliferation and neuronal differentiation when used at low concentrations. These protective effects are mediated by Wnt signaling pathway.
- Identification of a conserved cis-regulatory element controlling
mid-diencephalic expression of mouse Six3
- Authors: Bumwhee Lee; Jiyeon Yoon, Duc Tri Lam, Jaeseung Yoon, Kwanghee Baek, Yongsu Jeong
Abstract: The sine oculis homeobox protein Six3 plays pivotal roles in the development of the brain and craniofacial structures. In humans, SIX3 haploinsufficiency results in holoprosencephaly, a defect in anterior midline formation. Although much is known about the evolutionarily conserved functions of Six3, the regulatory mechanism responsible for the expression pattern of Six3 remains relatively unexplored. To understand how the transcription of Six3 is controlled during embryogenesis, we screened ∼300 kb of genomic DNA encompassing the Six3 locus for cis-acting regulatory elements capable of directing reporter gene expression to sites of Six3 transcription in transgenic mouse embryos. We identified a novel enhancer element, whose activity recapitulates endogenous Six3 expression in the ventral midbrain, pretectum, and thalamus. Cross-species comparisons revealed that this Six3 brain enhancer is functionally conserved in other vertebrates. We also showed that normal Six3 transcription in the ventral midbrain and pretectum is dependent on Ascl1, a basic helix-loop-helix proneural factor. Moreover, loss of Ascl1 resulted in downregulation of the Six3 brain enhancer activity, emphasizing its unique role in regulating Six3 expression in the developing brain.
- Issue Information
- Pages: 123 - 124
- INTRODUCTION: ALTERED URBAN LANDSCAPES: EUROPEAN CITIES IN TRANSITION
- Authors: Olga Medvedkov; Joseph Salukvadze
Pages: 287 - 288
- INFORMALITY AND LAND DEVELOPMENT IN ALBANIA: LAND REFORMS AND
SOCIOECONOMIC DYNAMICS IN A COASTAL SETTLEMENT
- Authors: Loukas Triantis; Fereniki Vatavali
Pages: 289 - 303
Abstract: Informality is a significant aspect of the recent processes of land development, which has attracted the interest of academics and policy-makers, in the context of the crucial role that land has acquired for the global economy and the prevalent trends of capitalist activity. A wide variety of reforms and policies for dealing with informality have been adopted in many countries worldwide, often under the guidance of supranational organisations, though with contradictory impacts.The objective of this article is the critical appraisal of informality in land development processes in Albania, a former socialist country in “transition”, by exploring links with land reforms and socioeconomic dynamics, as well as the interaction of various actors from the global to the local level. We argue that, through multiple synergies and conflicts, informal practices serve a wide variety of interests, while informality in itself, as well as the policies for controlling it, may also lead to the intensification of socio-spatial inequalities and exclusionsOur approach is based on the analysis of the land development processes in the coastal settlement of Jal as a case study. The article focuses on an incident of demolitions of informal constructions in Jal in 2007, which was associated with a World Bank's development project, as well as on the land development dynamics prior to and after this incident. We employed a mixed-method approach, based on qualitative tools, which combined fieldwork in Jal, semi-structured interviews in Jal, Tirana and Athens, evaluation of land reforms and review of official reports and articles in the local and national press.
- SHRINKING CITIES IN POST-SOCIALIST EUROPE: WHAT CAN WE LEARN FROM THEIR
ANALYSIS FOR THEORY BUILDING TODAY?
- Authors: Annegret Haase; Dieter Rink, Katrin Grossmann
Pages: 305 - 319
Abstract: In the final decades of the twentieth century, the post-industrial regions of western Europe and the US were hot-spots of urban shrinkage, and this also affected large areas in post-socialist countries. Despite ongoing calls for a better integration of diverse global urban experiences into theorization, post-socialist cities and their trajectories, as well as their experiences with rapid urban change, have been largely disregarded in general theory development.At the same time, we face a somewhat inconsistent situation in the theoretical discourse on urban development. There are requests for “new geographies of theory” or to regard all cities as “ordinary”, in order to include different types of narratives and experience into overall comparisons and/or theory building.Set against this background, this paper aims to deal with the case of shrinking post-socialist cities, that is, cities that are “excluded” from hegemonic discourses for two reasons: they are post-socialist and they are shrinking. In contrast to this situation, we understand shrinking post-socialist cities as valuable examples for strengthening the debate on current and future forms of, and determining factors for, general urbanization. At the focus of our paper, therefore, are the questions about what we can learn from the analysis of shrinking post-socialist cities for the general discourse, as well as for theory building for cities, and how we can overcome the observed reluctance to integrate the post-socialist experience into general theory development.The paper draws on an EU 7 FP research project finished in 2012 that comparatively analysed urban shrinkage across several regions of Europe, with a particular focus on post-socialist countries.
- (POST) COLONIAL ENCOUNTERS IN THE POSTSOCIALIST CITY: RESHAPING URBAN
SPACE IN SARAJEVO
- Authors: Gruia Badescu
Pages: 321 - 329
Abstract: This article argues that postcolonial lenses can be useful in understanding postsocialism in particular urban situations, examining the postsocialist city of Sarajevo as an arena of postcolonial practices, processes and relationships. The city discussed, Sarajevo, provides a rich example of entanglements and relationships, both historical and of more recent origin. The article discusses with a postcolonial lens processes of urban reconstruction, specific to Sarajevo as a “post-conflict city”, but focuses on later urban development patterns, which in fact echo the general trends of postsocialist urban transitions in the broader region. As such, the article aims to unpack how the flows of capital reflect a postcolonial configuration of relationships between local elites, international actors and urban space. The case of Turkish investments reflects an increasing re-forging of ties between the metropole and the former province of the Ottoman Empire. New relationships also emerge, but with similar dynamics – the cases of Saudi investment and the construction of the US Embassy are explored to highlight the role of the local elites. The article argues that the postcolonial lens is useful to explore the relationship between the local elites and international capital in postsocialist cities, highlighting processes, practices, and relationships that are complementary to political economy-based urban geographies.
- RESIDENTIAL SATISFACTION AND INTENTION TO MOVE: THE CASE OF PRAGUE'S NEW
- Authors: Petra Špačková; Nina Dvořáková, Martina Tobrmanová
Pages: 331 - 348
Abstract: Suburbanization has been a particularly significant process in transforming the metropolitan regions in Central and East European countries in the past two decades. Many critics emphasize the negative consequences of suburbanization, such as a low level of residential environment quality, and some of them anticipate that suburbanites' expectations would remain unfulfilled. Moreover, a growing body of literature describes the tendency for reurbanization and discusses the importance of back-to-the city moves. Few authors, however, have paid attention to the empirical evidence of the residential stability of suburban areas. Therefore, this paper seeks to investigate the relationship between the quality of the suburban environment, the everyday life experiences associated with suburbia, and reurbanization tendencies. Various aspects of residential satisfaction and intentions to move in the medium term were analysed using data from a questionnaire survey which was carried out in three case study sites within Prague's hinterland. In addition, major differences between groups of potential “stayers” and “movers” were examined to reveal key factors which lie behind intentions to move from current suburban homes. The results suggested a relatively high degree of stability and a reasonable overall satisfaction of new suburbanites with their residential environment. They also indicated that trigger moments in the decision-making process were more closely related to the changing needs of households than the wider residential environment. Based on the research results, we were able to hypothesize that (1) a strong out-migration from the suburban zone is rather unlikely in the near future, and (2) only a small proportion of new suburbanites are likely to engage in the reurbanization process.
- NEIGHBOURHOOD TRAJECTORIES IN THE INNER CITIES OF PRAGUE AND TALLINN: WHAT
AFFECTS THE SPEED OF SOCIAL AND DEMOGRAPHIC CHANGE?
- Authors: Jana Temelová; Jakub Novák, Anneli Kährik, Tiit Tammaru
Pages: 349 - 366
Abstract: This paper explores neighbourhood trajectories in the inner cities in terms of social and demographic change in a comparative perspective, and analyses the role of in situ change and residential mobility in this change. The research is based on a quantitative census-based study of Prague (the Czech Republic) and Tallinn (Estonia) at a detailed neighbourhood level. The study shows that in spite of many political and historical similarities, the differences in local regulatory mechanisms and local contexts have led to different urban outcomes. Institutional rigidity and long-term resistance to adjusting physical structures to a new social system have restrained change in Prague. The inner city of Tallinn has experienced much more social restructuring, replacements and displacements. High home-ownership rates, early rent de-regulation and no major public involvement in housing all contribute to the market-led urban change in Tallinn.
- WHOSE CITY' KYIV AND ITS RIVER AFTER SOCIALISM
- Authors: Roman Adrian Cybriwsky
Pages: 367 - 379
Abstract: This article looks at changing land use along the banks of the Dnipro River (formerly Dnieper River) in Kyiv, Ukraine (formerly Kiev) as an example of rising social inequality since the collapse of Soviet socialism. A working assumption is that tangible symbols of power and privilege such as lavish private housing and land development for profit are more evident in post-socialist society than they were during Communism, and that the amenity-rich river zone in the center of Kyiv is ripe for gentrification of beaches, parks, and high hills with river views. The research is based on detailed field work along the Dnipro and study of maps and air photographs. Our data indicate that prime space along the river is being appropriated by private interests for profit or personal use, often without respect to environmental considerations, treasured historic landscapes, and the rule of land use law. In this way, the historic character of Kyiv is being eroded, and public access to the river and its resources is reduced.
- Regional Coverage Maximization: Alternative Geographical Space Abstraction
- Authors: Daoqin Tong; Ran Wei
Pages: 125 - 142
Abstract: Analysis results are often found to vary with the way we abstract geographical space. When continuous geographic phenomena are abstracted, processed, and stored in a digital environment, some level of discretization is often employed. Information loss in a discretization process brings about uncertainty/error, and as a result research findings may be highly dependent on the particular discretization method used. This article examines one spatial problem concerning how to achieve the maximal regional coverage given a limited number of service facilities. Two widely used geographical space abstraction approaches are examined, the point-based representation and the area-based representation, and issues associated with each representation scheme are analyzed. To accommodate the limitations of the existing representation schemes, a mixed representation strategy is proposed along with a new maximal covering model. Experiments are conducted to site warning sirens in Dublin, Ohio. Results demonstrate the effectiveness of the mixed representation scheme in finding high-quality solutions when the regional coverage level is medium or high.
- Bi-objective Model for Optimal Number and Size of Circular Facilities
- Authors: Masashi Miyagawa
Pages: 143 - 154
Abstract: This article presents a bi-objective model for determining the number and size of finite size facilities. The objectives are to minimize both the average closest distance to facilities and the probability that a random line intersects facilities. The former represents the accessibility of customers, whereas the latter represents the interference to travelers. The average closest distance and the probability of intersecting facilities are derived for circular facilities randomly distributed in a circular city. The analytical expressions for the average closest distance and the probability of intersecting facilities demonstrate how the number and size of facilities affect the accessibility of customers and the interference to travelers. The model focuses on the tradeoff between the accessibility and interference, and the tradeoff curve provides planners with alternatives for the number and size of facilities.
- Can Dasymetric Mapping Significantly Improve Population Data Reallocation
in a Dense Urban Area?
- Authors: Jose M. Pavía; Isidro Cantarino
Pages: 155 - 174
Abstract: The issue of reallocating population figures from a set of geographical units onto another set of units has received a great deal of attention in the literature. Every other day, a new algorithm is proposed, claiming that it outperforms competitor procedures. Unfortunately, when the new (usually more complex) methods are applied to a new data set, the improvements attained are sometimes just marginal. The relationship cost-effectiveness of the solutions is case-dependent. The majority of studies have focused on large areas with heterogeneous population density distributions. The general conclusion is that as a rule more sophisticated methods are worth the effort. It could be argued, however, that when we work with a variable that varies gradually in relatively homogeneous small units, simple areal weighting methods could be sufficient and that ancillary variables would produce marginal improvements. For the case of reallocating census data, our study shows that, even under the above conditions, the most sophisticated approaches clearly yield the better results. After testing fourteen methods in Barcelona (Spain), the best results are attained using as ancillary variable the total dwelling area in each residential building. Our study shows the 3-D methods as generating the better outcomes followed by multiclass 2-D procedures, binary 2-D approaches and areal weighting and 1-D algorithms. The point-based interpolation procedures are by far the ones producing the worst estimates.
- Prioritizing Disaster Mapping Tasks for Online Volunteers Based on
Information Value Theory
- Authors: Yingjie Hu; Krzysztof Janowicz, Helen Couclelis
Pages: 175 - 198
Abstract: In recent years, online volunteers have played important roles in disaster response. After a major disaster, hundreds of volunteers are often remotely convened by humanitarian organizations to map the affected area based on remote sensing images. Typically, the affected area is divided using a grid-based tessellation, and each volunteer can select one grid cell to start mapping. While this approach coordinates the efforts of volunteers, it does not differentiate the priorities of different cells. As a result, volunteers may map grid cells in a random order. Due to the spatial heterogeneity, different cells may contain geographic information that is of different value to emergency responders. Ideally, cells that potentially contain more valuable information should be assigned higher priority for mapping. This article presents an analytical framework for prioritizing the mapping of cells based on the values of information contained in these cells. Our objective is to provide guidance for online volunteers so that potentially more important cells are mapped first. We present a method that is based on information value theory and focus on road networks. We apply this method to a number of simulated scenarios and to a real disaster mapping case from the 2015 Nepal earthquake.
- W Function: A New Distance-Based Measure of Spatial Distribution of
- Authors: Pavel Kukuliač; Jiří Horák
Pages: 199 - 214
Abstract: Distance-based methods are applied in various fields of research. In this paper, a new relative distance-based method, the W function, is introduced. This method contributes to the assessment of spatial patterns of economic activities using the stochastic Monte Carlo simulation, and supplements the typology of distance-based methods recently drawn up by Marcon and Puech. The capability of the W function is compared with results from the Kd and the recently defined m function methods, which are widely used for monitoring the spatial distribution of economic activities by considering several theoretical and empirical examples. The W function appears to provide more precise estimations of the density of economic activities compared to the m and Kd functions, particularly in cases of complex patterns such as double clustered distribution. It also appears to provide a more accurate evaluation of dispersion.
- Radon Predictions with Geographical Information System Covariates: From
Spatial Sampling to Modeling
- Authors: Sandra De Iaco; Sabrina Maggio, Monica Palma
Pages: 215 - 235
Abstract: Radon (Rn) is a potentially toxic gas in soil which may affect human health. Assessing Rn levels in soil gas usually requires enormous efforts in terms of time and costs, since the sampling protocol is very complex. In most cases, the variable under study is sparsely sampled over the domain and this could affect the reliability of the spatial predictions. For this reason, it is useful to incorporate, into the estimation procedure, some auxiliary variables, correlated with the in soil gas Rn concentrations (primary variable) and more densely available over the domain. On the basis of this latter aspect, it is even better if the covariates are derived from a geographical information system (GIS). In this article, the Rn sampling protocol used during a measurement campaign planned over a risk area is described and the process of deriving GIS covariates considered as secondary information for predicting the primary variable is clarified. Then, multivariate modeling and prediction of the Rn concentrations over the domain of interest are discussed and a comparative study regarding the performance of the prediction procedures is presented. Rn prone areas are also analyzed with respect to urban and school density. All these aspects can clearly support decisions on environmental and human safeguard.