24 research outputs found
Transnational solidarity, the refugees and open societies in Europe
The recent massive arrival of war refugees has challenged Europe’s political unity and fanned the flames of anti-Muslim populism. Both discourses have been framed in terms of ‘shifting solidarity’ between the European Union member states, their citizens and the refugees. At stake, the article argues, is the delineation of the collectivity linked by the obligation of solidarity. Drawing on insights from research conducted among Polish-born migrants in Germany about their practices and attitudes towards helping the refugees, and critically engaging with social theory, this article offers a new understanding of transnational solidarity. Transnational solidarity, it argues, needs to embrace the tension between cosmopolitan and particularistic ideas around belonging. The article suggests defining transnational solidarity as an outcome of socio-culturally and spatio-temporally specific interpretations of the norm of solidarity. As a heuristic device, transnational solidarity helps us to understand the shifting alliances for and against refugees in Europe.Peer Reviewe
Structure Determination of Disordered Metallic Sub-Monolayers by Helium Scattering: A Theoretical and Experimental Study
An approach based on He scattering is used to develop an atomic-level
structural model for an epitaxially grown disordered sub-monolayer of Ag on
Pt(111) at 38K. Quantum scattering calculations are used to fit structural
models to the measured angular intensity distribution of He atoms scattered
from this system. The structure obtained corresponds to narrowly size-dispersed
compact clusters with modest translational disorder, and not to fractals which
might be expected due to the low surface temperature. The clusters have up to
two layers in height, the lower one having few defects only. The relations
between specific features of the angular scattering distribution, and
properties such as the cluster sizes and shapes, the inter-cluster distance
distribution etc., are discussed. The results demonstrate the usefulness of He
scattering as a tool for unraveling new complex surface phases.Comment: 5 pages, 3 figures, to appear in Surf. Sci. Lett. Related papers
available at http://neon.cchem.berkeley.edu/~dani/He-papers.htm
Step Patterns on Vicinal Reconstructed Surfaces
Step patterns on vicinal reconstructed surfaces of noble metals
Au(110) and Pt(110), miscut towards the (100) orientation, are investigated.
The free energy of the reconstructed surface with a network of crossing
opposite steps is calculated in the strong chirality regime when the steps
cannot make overhangs. It is explained why the steps are not perpendicular to
the direction of the miscut but form in equilibrium a network of crossing steps
which make the surface to look like a fish skin. The network formation is the
consequence of competition between the -- predominantly elastic -- energy loss
and entropy gain. It is in agreement with recent scanning-tunnelling-microscopy
observations on vicinal Au(110) and Pt(110) surfaces.Comment: 11 pages with 5 eps figures in text. Uses psfig and elsart.sty
(ELSEVIER Science). To be published in Surf. Sc
He Scattering from Random Adsorbates, Disordered Compact Islands and Fractal Submonolayers: Intensity Manifestations of Surface Disorder
A theoretical study is made on He scattering from three fundamental classes
of disordered ad-layers: (a) Translationally random adsorbates, (b) disordered
compact islands and (c) fractal submonolayers. The implications of the results
to experimental studies of He scattering from disordered surfaces are
discussed, and a combined experimental-theoretical study is made for Ag
submonolayers on Pt(111). Some of the main theoretical findings are: (1)
Structural aspects of the calculated intensities from translationally random
clusters were found to be strongly correlated with those of individual
clusters. (2) Low intensity Bragg interference peaks appear even for scattering
from very small ad-islands, and contain information on the ad-island local
electron structure. (3) For fractal islands, just as for islands with a
different structure, the off-specular intensity depends on the parameters of
the He/Ag interaction, and does not follow a universal power law as previously
proposed in the literature. In the experimental-theoretical study of Ag on
Pt(111), we use first experimental He scattering data from low-coverage (single
adsorbate) systems to determine an empirical He/Ag-Pt potential of good
quality. Then, we carry out He scattering calculations for high coverage and
compare with experiments. The conclusions are that the actual experimental
phase corresponds to small compact Ag clusters of narrow size distribution,
translationally disordered on the surface.Comment: 36 double-spaced pages, 10 figures; accepted by J. Chem. Phys.,
scheduled to appear March 8. More info available at
http://www.fh.huji.ac.il/~dani
Stability of Disk and Stripe Patterns of Nanostructures at Surfaces
The ordering of two-dimensional Ag islands embedded in the Pt(111) surface layer has been investigated using He-atom scattering and scanning tunneling microscopy. At lower Ag coverage the embedded islands consist of compact clusters (disks) arranged into a short-range ordered two-dimensional array. At higher coverage the Ag islands have an elongated shape leading to a ''labyrinthine'' pattern of regularly spaced meandering stripes. As the temperature is increased, both the disk and stripe arrays of embedded Ag clusters transform reversibly into a disordered 2D Ag-Pt mixture. The observed behavior is explained in terms of strain-induced long-range interactions
Arachnoid cyst in a patient with psychosis: Case report
<p>Abstract</p> <p>Background</p> <p>The aetiology of a psychotic disturbance can be due to a functional or organic condition. Organic aetiologies are diverse and encompass organ failures, infections, nutritional deficiencies and space-occupying lesions. Arachnoid cysts are rare, benign space-occupying lesions formed by an arachnoid membrane containing cerebrospinal fluid (CSF). In most cases they are diagnosed by accident. Until recently, the coexistence of arachnoid cysts with psychiatric disturbances had not been closely covered in the literature. However, the appearance of some references that focus on a possible link between arachnoid cysts and psychotic symptoms has increased the interest in this subject and raised questions about the etiopathogeny and the therapeutic approach involved.</p> <p>Clinical presentation</p> <p>We present the clinical report of a 21-year-old man, characterised by the insidious development of psychotic symptoms of varying intensity, delusional ideas with hypochondriac content, complex auditory/verbal hallucinations in the second and third persons, and aggressive behaviour. The neuroimaging studies revealed a voluminous arachnoid cyst at the level of the left sylvian fissure, with a marked mass effect on the left temporal and frontal lobes and the left lateral ventricle, as well as evidence of hypoplasia of the left temporal lobe. Despite the symptoms and the size of the cyst, the neurosurgical department opted against surgical intervention. The patient began antipsychotic therapy and was discharged having shown improvement (behavioural component), but without a complete remission of the psychotic symptoms.</p> <p>Conclusion</p> <p>It is difficult to be absolutely certain whether the lesion had influence on the patient's psychiatric symptoms or not.</p> <p>However, given the anatomical and neuropsychological changes, one cannot exclude the possibility that the lesion played a significant role in this psychiatric presentation. This raises substantial problems when it comes to choosing a therapeutic strategy.</p
European solidarity as boundary-making: A conjoint analysis of attitudes towards Islam in the context of the ‘refugee crisis’
The arrival of refugees from predominantly Muslim countries in the core of Europe has fuelled discussions on European solidarity. This article explores the sources of solidarity in Europe in the aftermath of the ‘refugee crisis’ of 2015. By focusing on migrants’ attitudes towards refugees, the article considers solidarity in light of contradictory public discourses on refugees in Europe. Drawing on data from a survey among Polish migrants residing in Germany and applying a conjoint analysis, the article demonstrates that religion and gender are the main criteria for boundary-making between the respondents and the refugees. In this process, national and ethnic identities are subordinated to the idea of belonging to an imagined Christian community. Our results suggest that new exclusionary solidarities shaped by boundary-making between Christians and Muslim refugees are being established within Europe. As a result, Islamophobia emerges as a transnational European exclusionary project evading ethnic and national boundaries.Peer Reviewe
Untersuchungen zum heteroepitaktischen Wachstum im Submonolagenbereich mittels Streuung thermischer Heliumatome
Heteroepitaxial growth of thin metal films on metal surfaces has been analyzed in the submonolayer regime by thermal helium atom scattering (TEAS). Experiments have been performed on two different substrates: the non-reconstructed Pt(111) surface and the Au(111) surface which exhibits a long-range (~ 22 x )-reconstruction. Ag was deposited on the Pt substrate and Co on the Au substrate. Based on the analysis of the growth of Ag on Pt(111) it is found that below T = 45K the monomer is the stable nucleus. At these low temperatures small islands are formed with mean size and separation depending on the deposition rate and temperature. It is shown that these structures are not thermally stable and that their arrangement is governed by kinetic processes. Upon increasing the deposition temperature the size of the critical nucleus increases and the growth mode changes from a three dimensional growth to a layer-by-layer growth based on a "step flow" mechanism. At all temperatures the growth of the first Ag layer is pseudomorphic (i. e. with the same lattice parameter and orientation as the Pt(111) substrate). Surprisingly, at a deposition temperature of about T = 600 K, however, submonolayer deposition of Ag again leads to the formation of small islands with an initial diameter of about 10 . Furthermore, these islands are arranged in a rather regular pattern. The size as well as the separation of the islands depends neither on the deposition rate nor on the deposition temperature. To generate this structure the Pt(111) surface covered with submonolayer amounts of Ag only has to be heated once above a critical temperature of about T = 600 K. It is demonstrated that these quasi-regularly arranged islands represent the thermal equilibrium configuration. For this phase two distinct structural phase transitions are observed: (i) Upon increasing the Ag coverage the structure of the Ag islands changes from a two-dimensional array of compact islands (disk phase) with an average separation of about 30 at = 0.2 ML to a one-dimensional "striped" pattern at coverages around = 0.5 ML with approximately the same average distance of 30 but no preferential orientation of the stripes. (ii) An order-/ disorder-transition with a critical temperature of about T = 620 K. At low coverage (disk phase) the regular arrangement of the islands is destroyed whereas at higher coverage (stripe phase) the one-dimensional structure startsto meander and to disintegrate into smaller clusters. The existence of disk and stripe phases as well as the observed transitions can be understood within a simple model based on elastic interactions (originating from the lattice mismatch of the Ag adlayer and the Pt(111) substrate). A main result of this model is that the ratio between the initial size of an island and the minimum separation between islands (i. e. the minimum periodicity of the pattern) is 1/3 and that this ratio does not depend on the symmetry of the pattern (stripes vs. disks). This result is corroborated by the present experiments. A comparison of the structure with a regular arrangement of Ag islands obtained after [...
Biographical Reconstructive Network Analysis (BRNA): A Life Historical Approach in Social Network Analysis of Older Migrants in Australia
While qualitative approaches in social network analysis have been flourishing, the research processes, especially data analysis, are still often informed by the structural network analysis paradigm. Furthermore, there is a lack of analytical approaches and systematic discussion on possible ways to analyze network data collected in the qualitative interpretative research paradigm. To close this gap, we propose a methodological approach that builds on the cultural turn in social network analysis that advocates a focus on subjective patterns of interpretation and historical/processual configurations. We formulate a biographical network analytical perspective, analyzing the development of a social network through a person's life history. Based on a case study derived from a research project on transnational support networks of older migrants in Perth, Australia, we aim to explicate the analytical procedure of the biographical reconstructive network analysis (BRNA). BRNA is a collaboratively developed analytical procedure for social network data collection and analysis. During the BRNA data collection, both the biographical-narrative interview and ego-centric network maps are implemented. The BRNA data analysis procedure is informed by biographical reconstructive research principles to fully understand and reconstruct the dynamics of social networks during the life course.Während qualitative Ansätze in der sozialen Netzwerkanalyse florieren, sind Forschungsprozesse und insbesondere die Datenanalyse zumeist von einem strukturalen netzwerkanalytischen Paradigma geprägt. Zudem existieren unzureichend qualitativ-interpretative Ansätze zur Untersuchung sozialer Netzwerkdaten. Um diese Forschungslücke zu schließen, entwerfen und explizieren wir ein qualitatives Analyseverfahren, das auf dem Cultural Turn der sozialen Netzwerkanalyse aufbaut und sowohl subjektive Deutungsmuster als auch historisch/prozessuale Konfigurationen erfassen soll. Wir formulieren eine biografische netzwerkanalytische Perspektive, in der wir die Entwicklung eines sozialen Netzwerkes in der Lebensgeschichte analysieren. Am Beispiel einer Fallstudie aus einem Forschungsprojekt zu transnationalen sozialen Unterstützungsnetzwerken älterer Migrant*innen in Perth explizieren wir das Verfahren der biografisch rekonstruktiven Netzwerkanalyse (BRNA). BRNA ist ein kooperativ entwickeltes analytisches Verfahren der Erhebung und der Auswertung sozialer Netzwerkdaten. Bei der BRNA-Datenerhebung werden das narrativ-biografische Interview und ego-zentrische Netzwerkkarten trianguliert. Bei der Datenanalyse folgen wir biografisch-rekonstruktiven Forschungsprinzipien und Verfahren, um die Dynamiken sozialer Netzwerke in der Lebensgeschichte zu rekonstruieren und nachzuvollziehen
Biographical Reconstructive Network Analysis (BRNA): A Life Historical Approach in Social Network Analysis of Older Migrants in Australia
While qualitative approaches in social network analysis have been flourishing, the research processes, especially data analysis, are still often informed by the structural network analysis paradigm. Furthermore, there is a lack of analytical approaches and systematic discussion on possible ways to analyze network data collected in the qualitative interpretative research paradigm. To close this gap, we propose a methodological approach that builds on the cultural turn in social network analysis that advocates a focus on subjective patterns of interpretation and historical/processual configurations. We formulate a biographical network analytical perspective, analyzing the development of a social network through a person's life history. Based on a case study derived from a research project on transnational support networks of older migrants in Perth, Australia, we aim to explicate the analytical procedure of the biographical reconstructive network analysis (BRNA). BRNA is a collaboratively developed analytical procedure for social network data collection and analysis. During the BRNA data collection, both the biographical-narrative interview and ego-centric network maps are implemented. The BRNA data analysis procedure is informed by biographical reconstructive research principles to fully understand and reconstruct the dynamics of social networks during the life course.Während qualitative Ansätze in der sozialen Netzwerkanalyse florieren, sind Forschungsprozesse und insbesondere die Datenanalyse zumeist von einem strukturalen netzwerkanalytischen Paradigma geprägt. Zudem existieren unzureichend qualitativ-interpretative Ansätze zur Untersuchung sozialer Netzwerkdaten. Um diese Forschungslücke zu schließen, entwerfen und explizieren wir ein qualitatives Analyseverfahren, das auf dem Cultural Turn der sozialen Netzwerkanalyse aufbaut und sowohl subjektive Deutungsmuster als auch historisch/prozessuale Konfigurationen erfassen soll. Wir formulieren eine biografische netzwerkanalytische Perspektive, in der wir die Entwicklung eines sozialen Netzwerkes in der Lebensgeschichte analysieren. Am Beispiel einer Fallstudie aus einem Forschungsprojekt zu transnationalen sozialen Unterstützungsnetzwerken älterer Migrant*innen in Perth explizieren wir das Verfahren der biografisch rekonstruktiven Netzwerkanalyse (BRNA). BRNA ist ein kooperativ entwickeltes analytisches Verfahren der Erhebung und der Auswertung sozialer Netzwerkdaten. Bei der BRNA-Datenerhebung werden das narrativ-biografische Interview und ego-zentrische Netzwerkkarten trianguliert. Bei der Datenanalyse folgen wir biografisch-rekonstruktiven Forschungsprinzipien und Verfahren, um die Dynamiken sozialer Netzwerke in der Lebensgeschichte zu rekonstruieren und nachzuvollziehen