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See detailLocalization of Nopp140 within mammalian cells during interphase and mitosis.
Thiry, Marc ULg; Cheutin, Thierry; Lamaye, Françoise ULg et al

in Histochemistry & Cell Biology (2009), 132(2), 129-40

We investigated distribution of the nucleolar phosphoprotein Nopp140 within mammalian cells, using immunofluorescence confocal microscopy and immunoelectron microscopy. During interphase, three ... [more ▼]

We investigated distribution of the nucleolar phosphoprotein Nopp140 within mammalian cells, using immunofluorescence confocal microscopy and immunoelectron microscopy. During interphase, three-dimensional image reconstructions of confocal sections revealed that nucleolar labelling appeared as several tiny spheres organized in necklaces. Moreover, after an immunogold labelling procedure, gold particles were detected not only over the dense fibrillar component but also over the fibrillar centres of nucleoli in untreated and actinomycin D-treated cells. Labelling was also consistently present in Cajal bodies. After pulse-chase experiments with BrUTP, colocalization was more prominent after a 10- to 15-min chase than after a 5-min chase. During mitosis, confocal analysis indicated that Nopp140 organization was lost. The protein dispersed between and around the chromosomes in prophase. From prometaphase to telophase, it was also detected in numerous cytoplasmic nucleolus-derived foci. During telophase, it reappeared in the reforming nucleoli of daughter nuclei. This strongly suggests that Nopp140 could be a component implicated in the early steps of pre-rRNA processing. [less ▲]

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See detailLocalization of nucleic acids in hepatocyte nucleoli of rats upon D-galactosamine-induced block of transcription.
Mikhaylova, V. T.; Thiry, Marc ULg; Stephanova, E. et al

in Experimental Cell Research (1996), 225(2), 389-98

The precise localization of DNA and RNA within rat hepatocyte nucleoli during the process of D-galactosamine-induced nucleolar segregation has been studied by using sensitive methods for their detection ... [more ▼]

The precise localization of DNA and RNA within rat hepatocyte nucleoli during the process of D-galactosamine-induced nucleolar segregation has been studied by using sensitive methods for their detection: osmium-ammine staining and terminal deoxynucleotidyl transferase reaction for DNA, and immunoelectron microscopy with anti-RNA antibodies, RNase-gold, and autoradiography with tritiated orotic acid for RNA. The blocking of transcription was followed by the disappearance of intranucleolar condensed chromatin. Agglomerates of thin extended DNA filaments were found to change their location to the nucleolar periphery and to coalesce with each other. At the last stage of nucleolar segregation they were concentrated at the pole of the nucleolar fibrillar remnant while the rest of the nucleolus did not contain any DNA. No DNA was found in the dense fibrillar component of both intact and treated hepatocyte nucleoli. During the process of nucleolar segregation the bulk of the nucleolar RNA was found within the so-called spherical bodies. This RNA appeared to be synthesized shortly before or even after drug administration. The results obtained are in agreement with the hypothesis that the fibrillar centers are the site of nucleolar transcription. They also show that uncompleted molecules of pre-rRNA whose synthesis has been blocked are segregated from the rest of nucleolar RNA species into the spherical bodies. [less ▲]

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See detailLocalization of nucleolar chromatin by immunocytochemistry and in situ hybridization at the electron microscopic level.
Thiry, Marc ULg; Scheer, U.; Goessens, Guy ULg

in Electron Microscopy Reviews (1991), 4(1), 85-110

Nucleoli are the morphological expression of the activity of a defined set of chromosomal segments bearing rRNA genes. The topological distribution and composition of the intranucleolar chromatin as well ... [more ▼]

Nucleoli are the morphological expression of the activity of a defined set of chromosomal segments bearing rRNA genes. The topological distribution and composition of the intranucleolar chromatin as well as the definition of nucleolar structures in which enzymes of the rDNA transcription machinery reside have been investigated in mammalian cells by various immunogold labelling approaches at the ultrastructural level. The precise intranucleolar location of rRNA genes has been further specified by electron microscopic in situ hybridization with a non-autoradiographic procedure. Our results indicate that the fibrillar centers are the sole nucleolar structures where rDNA, core histones, RNA polymerase I and DNA topoisomerase I are located together. Taking into account the potential value and limitations of immunoelectron microscopic techniques, we propose that transcription of the rRNA genes takes place within the confines of the fibrillar centers, probably close to the boundary regions to the surrounding dense fibrillar component. [less ▲]

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See detailLocalization of oestrogen receptors in the sensory and motor areas of the spinal cord in Japanese quail (Coturnix japonica)
Evrard, H. C.; Balthazart, Jacques ULg

in Journal of Neuroendocrinology (2002), 14(11), 894-903

In Japanese quail, the presence of aromatase (oestrogen synthase) in the dorsal horn of the spinal cord suggests that spinal sensory processes might be controlled by local actions of oestrogens. This is ... [more ▼]

In Japanese quail, the presence of aromatase (oestrogen synthase) in the dorsal horn of the spinal cord suggests that spinal sensory processes might be controlled by local actions of oestrogens. This is supported by the presence of oestrogen receptors and aromatase in the dorsal horn of the spinal cord in rats, and by the alteration of sensitivity by oestrogens in various mammalian species and also in canaries. We investigated whether oestrogens that are locally produced in the quail spinal cord can bind to specific receptors in the vicinity of their site of synthesis. We demonstrate the presence of numerous oestrogen receptor alpha-immunoreactive (ERalpha-ir) cell nuclei, predominantly in laminae II and, to a lesser extent, I and III of the dorsal horn of the spinal cord (i.e. in the area where aromatase was previously identified). ERalpha-ir cells were also seen in various parts of the intermediate zone (laminae V-VII). This presence of ERalpha-ir cells in the dorsal horn and intermediate zone fits in well with the distribution of ERalpha-ir cells in homologous areas in mammals, including rats. Only a few labelled cells were found in the ventral horn in the cervical, brachial, thoracic and first lumbar segments, but a conspicuous dense group of large ERalpha-ir cells was identified in lamina IX of the ventral horn in synsacral segments 8-10, which contain the motoneurones innervating the muscles of the cloacal gland. The presence of ERalpha-ir cells in lamina IX of these synsacral segments in quail contrasts with the finding that motoneurones innervating penile muscles in rats contain androgen, but not oestrogen receptors, and are influenced by androgens rather than by oestrogens. Together, these data suggest that spinal actions of oestrogens may modulate the sensory and motor systems that participate in reproduction, as well as other nonreproductive functions in quail. [less ▲]

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See detailLocalization of superconductivity in superconductor–electromagnet hybrids
Ataklti, G.W.; Aladyshkin, A.Yu.; Gillijns, W. et al

in Superconductor Science and Technology (2012), 25

We investigate the nucleation of superconductivity in a superconducting Al strip under the influence of the magnetic field generated by a current-carrying Nb wire, perpendicularly oriented and located ... [more ▼]

We investigate the nucleation of superconductivity in a superconducting Al strip under the influence of the magnetic field generated by a current-carrying Nb wire, perpendicularly oriented and located underneath the strip. The inhomogeneous magnetic field, induced by the Nb wire, produces a spatial modulation of the critical temperature Tc, leading to a controllable localization of the superconducting order parameter (OP) wavefunction. We demonstrate that close to the phase boundary Tc(Bext) the localized OP solution can be displaced reversibly by either applying an external perpendicular magnetic field Bext or by changing the amplitude of the inhomogeneous field. [less ▲]

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See detailLocalization of Testosterone-Sensitive and Sexually Dimorphic Aromatase-Immunoreactive Cells in the Quail Preoptic Area
Balthazart, Jacques ULg; Tlemcani, O.; Harada, N.

in Journal of Chemical Neuroanatomy (1996), 11(3), 147-71

The distribution of aromatase-immunoreactive cells was studied in the medial preoptic nucleus of male and female quail that were sexually mature and gonadally intact, or gonadectomized, or gonadectomized ... [more ▼]

The distribution of aromatase-immunoreactive cells was studied in the medial preoptic nucleus of male and female quail that were sexually mature and gonadally intact, or gonadectomized, or gonadectomized and treated with testosterone. The study first confirmed the existence of a significant difference in the number of aromatase-immunoreactive cells between males and females (males > females) and the marked effect of castration and testosterone treatment which, respectively, decrease and restore the number of these cells. An analysis of the distribution in space of this neurochemically defined cell population was also carried out. This study revealed that castration does not uniformly decrease the density of aromatase-immunoreactive cells, but local increases are observed in an area directly adjacent to the third ventricle. A number of new sex differences in the organization of the medial preoptic nucleus and its population of aromatase cells have, in addition, been identified. The density of aromatase-immunoreactive cells is not higher in males than in females throughout the nucleus, but a higher density of immunoreactive cells is present in the ventromedial part of the nucleus in females as compared to males. In addition, the cross-sectional area of the nucleus as defined by the population of aromatase-immunoreactive cells is larger in males than in females in its rostral part and its shape is more elongated in the dorso-ventral direction in females than in males. Some of these differences (e.g. higher density of ARC-ir cells in the ventromedial part of the female POM, shape of the nucleus) appear to be organizational in nature, because they are still present in birds exposed to the same endocrine conditions during adult life (e.g. gonadectomized and treated with a same dose of testosterone). This conclusion should now be tested by experiments manipulating the endocrine environment of quail embryos. The anatomical heterogeneity of the medial preoptic nucleus revealed by this study also suggests a functional heterogeneity and the specific roles of the medial and lateral parts of the nucleus should also be investigated. [less ▲]

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See detailLocalization of the collagenous component in skin basement membrane.
Yaoita, H.; Foidart, Jean-Michel ULg; Katz, S. I.

in Journal of Investigative Dermatology (1978), 70(4), 191-3

Antibodies to type IV collagen were produced by immunizing rabbits with a basement membrane collagen obtained from a transplantable mouse tumor. Using specifically purified antibodies, type IV collagen ... [more ▼]

Antibodies to type IV collagen were produced by immunizing rabbits with a basement membrane collagen obtained from a transplantable mouse tumor. Using specifically purified antibodies, type IV collagen was localized ultrastructurally to the basal lamina part of the basement membrane zone [less ▲]

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See detailLocalization of the human KRAB finger gene ZNF117 (HPF9) to chromosome 7q11.2
Bellefroid, Eric J.; Ried, Thomas; Riviere, Michele et al

in Genomics (1992), 14(3), 780-1

A cluster of Kruppel type zinc finger genes of the KRAB subclass has recently been localized on human chromosome 19p12-p13.1. We now report that ZNF117 (HPF9), a closely related zinc finger gene of this ... [more ▼]

A cluster of Kruppel type zinc finger genes of the KRAB subclass has recently been localized on human chromosome 19p12-p13.1. We now report that ZNF117 (HPF9), a closely related zinc finger gene of this KRAB subfamily, has been assigned to a distinct locus in the human genome: chromosome band 7q11.2. [less ▲]

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See detailLocalization of type I, III, IV collagen and fibronectin in benign tumors and epitheliomas of the human breast
Pages, A.; Foidart, Jean-Michel ULg; Gordenne, W.

in Journal de Gynécologie, Obstétrique et Biologie de la Reproduction (1984), 13(1), 35-40

Fibronectin and types I, III and IV collagens were localized by an indirect immunofluorescence technique in 10 fibro-adenomas and 27 mammary adenocarcinomas. In the benign lesions, a densification of a ... [more ▼]

Fibronectin and types I, III and IV collagens were localized by an indirect immunofluorescence technique in 10 fibro-adenomas and 27 mammary adenocarcinomas. In the benign lesions, a densification of a type III collagen meshwork was noted around galactophoric channels. In carcinomas, various patterns of connective tissue proteins distributions were observed depending upon the histological types of lesions. Connective tissue proteins are restricted to the perivascular areas in mucinous carcinomas. Type III collagen is largely distributed in the stroma of poorly differentiated tumors. In differentiated carcinomas, discontinuous linear deposits of type IV collagen or fibronectin are localized at the border of epithelial proliferations. They probably represent the remmants of epithelial basement membrane. In intra- canalar adenocarcinomas, type IV collagen and fibronectin form irregular and discontinuous depositifs . These finding indicate that extensive connective tissue remodelling is observed during neoplastic infiltration. The type of stroma and connective tissue proteins distributed in these epithelial proliferations depends primarily upon the histological type of malignant infiltrating carcinomas. [less ▲]

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See detailLocalization of varicella-zoster virus nucleic acids and proteins in human skin.
Nikkels, Arjen ULg; Debrus, S.; Sadzot-Delvaux, Catherine ULg et al

in Neurology (1995), 45(12 Suppl 8), 47-9

The pathogenic mechanisms involved in varicella-zoster virus (VZV) infections remain elusive. The pattern of cutaneous distribution of the IE63 protein and of the gpI (gE) and gpII glycoproteins with ... [more ▼]

The pathogenic mechanisms involved in varicella-zoster virus (VZV) infections remain elusive. The pattern of cutaneous distribution of the IE63 protein and of the gpI (gE) and gpII glycoproteins with their corresponding genome sequences during VZV infections was studied by immunohistochemistry and in situ hybridization. Skin biopsy specimens were obtained from immunocompetent and immunocompromised patients with varicella, herpes zoster, or atypical VZV lesions. The first evidence for VZV infection consisted of the presence of IE63 in keratinocytes. In the vesicles and pustules, the viral transcripts gpI, gpII, and IE63 and the corresponding nucleic acids for gpI and gpII were identified in keratinocytes, sebocytes, Langerhans cells, dermal dendrocytes, monocytes/macrophages, and endothelial cells. The gpI and gpII glycorpoteins were essentially located on the cellular membranes while IE63 expression was generally restricted to the nuclei. In three biopsies of early herpes zoster, viral proteins were disclosed in dermal nerves and in perineurial type I dendrocytes. This was never encountered in varicella. Vasculitic changes and endothelial cell involvement were more prominent in varicella than in herpes zoster. It is concluded that the secondary viremia in varicella that affects the dermal endothelial cells is followed by a cell-to-cell spread to keratinocytes. In herpes zoster, the viral progression through cutaneous nerves primarily extends to the pilosebaceous units with a secondary involvement of epidermal keratinocytes, followed by a further spread to dermal cells. [less ▲]

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See detailLocalized electron dynamics in attosecond-pulse-excited molecular systems: Probing the time-dependent electron density by sudden photoionization
Mignolet, Benoît ULg; Levine, Raphael; Remacle, Françoise ULg

in Physical Review. A (2012)

Ultrafast UV excitation can prepare a nonstationary coherent superposition of molecular electronic states. The purely electronic dynamics before the onset of nuclear motion can be probed by a sudden XUV ... [more ▼]

Ultrafast UV excitation can prepare a nonstationary coherent superposition of molecular electronic states. The purely electronic dynamics before the onset of nuclear motion can be probed by a sudden XUV ionization of the electronic wave packet. Dynamical computations at the many-electron level on the LiH and 1-azabicyclo[3.3.3]undecane (C10H19N) molecules showthat molecular frame photoelectron angular distributions reflect the spatial localization and undulations of the electronic coherent superposition accessed by the initial ultrafast UV excitation. The sudden ionization is sensitive to interference effects. [less ▲]

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See detailLocalized failure in saturated porous media
Desrues, Jacques; Collin, Frédéric ULg

in Vermeer, Peter; Ehlers, W.; Herrmann, H. J. (Eds.) Modelling of Cohesive-Frictionl Materials (2004)

Strain localisation in soils and rocks has been studied extensively for the last 20 years. A part of these studies have been devoted to the response of specimens submitted to tests in undrained situation ... [more ▼]

Strain localisation in soils and rocks has been studied extensively for the last 20 years. A part of these studies have been devoted to the response of specimens submitted to tests in undrained situation. It was shown that shear banding can take place in both contractive and dilative specimens, with some special features due to the coupling between the granular skeleton and the pore fluid. In the paper, the relevance of the bifurcation criterion in shear band mode in the case of hydromechanical coupling is assessed by numerical study of the response of the constitutive model CLoE –the Hypoplastic model developed in L3S-Grenoble– in two kinds of numerical integration: local, i.e. at the material point level and global, i.e. in boundary value problems analyzed by finite elements. [less ▲]

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See detailLocalized iterative generalized multipole technique for large two-dimensional scattering problems
Obelleiro, Fernando; Landesa, Luis; Rodriguez, Jose Luis et al

in Ieee Transactions On Antennas And Propagation (2001), 49(6), 961-970

In this work, we propose a novel and efficient solution for the generalized multipole technique (GMT): the localized iterative generalized multipole technique (LIGMT). In LIGMT, an analytic constraint is ... [more ▼]

In this work, we propose a novel and efficient solution for the generalized multipole technique (GMT): the localized iterative generalized multipole technique (LIGMT). In LIGMT, an analytic constraint is imposed on the power radiated by the set of multipole sources sharing the same origin, rendering it minimum over a given angular sector. In this way, the power radiated by each set of multipoles is confined to a different section of the scatterer surface. It follows that each set of multipole coefficients can be solved step by step via an iterative process, which circumvents the need to solve the large and full matrix equation. This implies a significant reduction of the computational and storage cost, enhancing the scope of application of the GMT method to larger problems. [less ▲]

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See detaillocalized modulation of testosterone action: Function of steroid receptor coactivators in the brain
Charlier, Thierry ULg; Balthazart, Jacques ULg

in Ardis, L. I. (Ed.) New research on testosterone (2008)

Testosterone, through its activation of androgen and estrogen receptors, has been shown to play a critical role in brain development and physiology. Recent studies have shown that the activity of these ... [more ▼]

Testosterone, through its activation of androgen and estrogen receptors, has been shown to play a critical role in brain development and physiology. Recent studies have shown that the activity of these receptors can be modulated by the interaction with several proteins and, in particular, that coactivators are required to enhance their transcriptional activity. The steroid receptor coactivator-1, SRC-1 is the best-characterized coactivator and we review here the current knowledge on the distribution, regulation of expression and function of this protein in the brain, focusing mostly on our work in Japanese quail. As expected for a ubiquitous coactivator, SRC-1 is present throughout the brain in both mammalian and avian species but is found in particularly high concentrations in testosterone-sensitive areas such as the preoptic area in rat and Japanese quail and in the song control nuclei in songbirds. Further analysis demonstrates that the expression of SRC-1 is not constitutive but regulated in specific brain areas by the sex, acute stress and testosterone treatment. In addition, the protein concentration appears to fluctuate through the day in some brain regions. These modulations of SRC-1 expression by endogenous (sex) and exogenous (stress) factors could potentially exacerbate at specific times the competition or squelching between different nuclear receptors and therefore decrease the biological response induced by one or another hormonal system. Although the existence of such a phenomenon has not yet been demonstrated in a functionally intact biological system, the effects of SRC-1 antisense treatments clearly strengthen this hypothesis. Indeed, the decrease of SRC-1 expression in the hypothalamus induced by antisense oligonucleotide injections clearly inhibited both estrogen-dependent male sexual behavior and androgen-dependent pre- and post-copulatory displays (strut) in Japanese quail, therefore demonstrating a role of the coactivator in the transcriptional activation induced by both estrogen and androgen receptors. Interestingly, the inhibitory effect on sexual behavior of SRC-1 knock down was not systematically associated with modifications of several histological (definition of median preoptic nucleus [POM] using Nissl staining), immunohistochemical (aromatase and vasotocin cells and fibers in the POM) and biochemical (aromatase enzymatic activity) markers of testosterone action in the brain. This dissociation of the effects of SRC-1 on behavior on the one hand and on aromatase and POM neurochemistry on another hand suggests that other system(s) involved in the activation of male sexual behavior are likely more sensitive to a decrease of SRC-1 expression. In future research, it will be essential to determine the other cofactors involved in specific physiological responses and to define whether these coactivators act synergistically, in parallel or independently in the modulation of the activity of one or several nuclear receptors linked to a particular physiological event. In several biological models, the observed changes in concentration of the circulating hormone and /or its receptors are apparently not sufficient to explain the physiological and behavioral responses observed after testosterone treatment. The discovery of steroid receptor coactivators opens new perspectives in the study of the molecular basis of steroid action at the level of the organism and a complete understanding of the mechanisms of steroid action will not be achieved without a detailed characterization of nuclear receptor cofactors. [less ▲]

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See detailLocalizing and comparing weight maps generated from linear kernel machine learning models
Schrouff, Jessica ULg; CREMERS, Julien ULg; GARRAUX, Gaëtan ULg et al

in 2013 Third International Workshop on Pattern Recognition in NeuroImaging (PRNI 2013): proceedings (2013)

Recently, machine learning models have been applied to neuroimaging data, allowing to make predictions about a variable of interest based on the pattern of activation or anatomy over a set of voxels ... [more ▼]

Recently, machine learning models have been applied to neuroimaging data, allowing to make predictions about a variable of interest based on the pattern of activation or anatomy over a set of voxels. These pattern recognition based methods present undeniable assets over classical (univariate) techniques, by providing predictions for unseen data, as well as the weights of each voxel in the model. However, the obtained weight map cannot be thresholded to perform regionally specific inference, leading to a difficult localization of the variable of interest. In this work, we provide local averages of the weights according to regions defined by anatomical or functional atlases (e.g. Brodmann atlas). These averages can then be ranked, thereby providing a sorted list of regions that can be (to a certain extent) compared with univariate results. Furthermore, we defined a “ranking distance”, allowing for the quantitative comparison between localized patterns. These concepts are illustrated with two datasets. [less ▲]

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See detailLOCALLY BOUNDED NONCONTINUOUS LINEAR-FORMS ON STRONG DUALS OF NONDISTINGUISHED KOTHE ECHELON SPACES
Bastin, Françoise ULg; Bonet, Jose

in Proceedings of the American Mathematical Society (1990), 108(3), 769-774

In this note it is proved that if Al (A) is any nondistinguished Kothe echelon space of order one and K. ,0 (AI (A))' is its strong dual, then there is even a linear form : K - C which is locally bounded ... [more ▼]

In this note it is proved that if Al (A) is any nondistinguished Kothe echelon space of order one and K. ,0 (AI (A))' is its strong dual, then there is even a linear form : K - C which is locally bounded (i.e. bounded on the bounded sets) but not continuous. It is also shown that every nondistinguished Kothe echelon space contains a sectional subspace with a particular structure [less ▲]

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See detailLocating carbon nanotubes (CNTs) at the surface of polymer microspheres using poly(vinyl alcohol) grafted CNTs as dispersion co-stabilizers
Thomassin, Jean-Michel ULg; Molenberg, Isabel; Huynen, Isabelle et al

in Chemical Communications (2010), 46(3330), 3332

In this communication, we prepared carbon nanotubes (CNTs) modified by poly(vinyl alcohol) that are used as co-stabilizers for the dispersion polymerization of methyl methacrylate. Poly(methyl ... [more ▼]

In this communication, we prepared carbon nanotubes (CNTs) modified by poly(vinyl alcohol) that are used as co-stabilizers for the dispersion polymerization of methyl methacrylate. Poly(methyl methacrylate) microspheres with CNTs selectively located at their surface are formed. This specific localization is a way to enhance the electrical conductivity of the nanocomposite. [less ▲]

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See detailLocating Migration: Rescaling Cities and Migrants
Martiniello, Marco ULg

in Glick Schiller, Nina; Çagglar, Ayse (Eds.) Locating Migration: Rescaling Cities and Migrants (2011)

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