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The globally distributed sperm whale (Physeter macrocephalus) has a partly matrilineal social structure with predominant male dispersal. At the beginning of 2016, a total of 30 male sperm whales stranded in five different countries bordering the southern North Sea. It has been postulated that these individuals were on a migration route from the north to warmer temperate and tropical waters where females live in social groups. By including samples from four countries (n = 27), this event provided a unique chance to genetically investigate the maternal relatedness and the putative origin of these temporally and spatially co-occuring male sperm whales. To utilize existing genetic resources, we sequenced 422 bp of the mitochondrial control region, a molecular marker for which sperm whale data are readily available from the entire distribution range. Based on four single nucleotide polymorphisms (SNPs) within the mitochondrial control region, five matrilines could be distinguished within the stranded specimens, four of which matched published haplotypes previously described in the Atlantic. Among these male sperm whales, multiple matrilineal lineages co-occur. We analyzed the population differentiation and could show that the genetic diversity of these male sperm whales is comparable to the genetic diversity in sperm whales from the entire Atlantic Ocean. We confirm that within this stranding event, males do not comprise maternally related individuals and apparently include assemblages of individuals from different geographic regions. (c) 2017 Deutsche Gesellschaft fur Saugetierkunde. Published by Elsevier GmbH. All rights reserved.
Im vorliegenden Beitrag steht das Zusammenspiel von institutioneller Kompetenzverteilung im föderalen Mehrebenensystem und Funktionsfähigkeit der Verwaltung im Bereich der Integrationspolitik im Zentrum. Dieser Verwaltungsbereich gewinnt zunehmend an Bedeutung, da sich für den Personenkreis der ca. 983.000 anerkannten Flüchtlinge, die länger oder dauerhaft in Deutschland bleiben werden, inzwischen neue Problemlagen ergeben, welche vor allem Fragen der Arbeitsmarktintegration, Aus- und Weiterbildung und berufsbezogenen Sprachförderung betreffen. Es wird der Leitfrage nachgegangen, welche institutionellen Strukturen und Aufgabenprofile sich im Bereich der Integrationsverwaltung im föderalen Mehrebenensystem herausgebildet haben und inwieweit diese sich als funktional und leistungsfähig oder als reformbedürftig erwiesen haben. Dabei wird auf Aspekte der Zentralisierung, Dezentralisierung und Verwaltungsverflechtung als wesentliche Institutionalisierungsoptionen eingegangen und aufgezeigt, dass in einigen Bereichen mehr Entflechtung in Form von Dezentralisierung und Aufgabenabschichtung „nach unten“ sinnvoll erscheint, während in anderen Handlungsfeldern verstärkte Bündelung und (besser funktionierende) Verwaltungsverflechtung angebracht wären.
Begriffe wie „Türken“, „Menschen mit türkischem Migrationshintergrund“, etc., die in vielen Bereichen des Lebens verwendet werden, sind Ausdruck der vorliegenden Differenzordnungen und Machtstrukturen und können diskriminierend wirken. Das ist z.B. dann der Fall, wenn bestimmte Begriffe verwendet werden, obwohl eine Kontextrelevanz nicht unbedingt vorliegt. Einige ethnische Bezeichnungen werden dabei häufiger verwendet als andere, trotz vergleichbarer Kontextrelevanz: „türkische/arabische Kinder“ aber nicht „englische/spanische Kinder“ (Wiese 2012), „Deutsch-Türke“ Mesut Özil aber nicht „Deutsch-Tunesier“ Sami Khedira. Erst die Bezeichnungen schaffen hier die Subjekte. Die besondere Auszeichnung macht es in der Folge möglich, dass ihnen Eigenschaften zugeschrieben werden (do Mar Castro Varela/Dhawan 2004). Aus Studien geht hervor, dass Ethnisierung mit Unterschichtung (Hormel 2007) in Verbindung gebracht wird und Begriffe wie „Migrant“ mit negativen Eigenschaften (Scarvagliere/Zech 2013). Durch die Auszeichnung von Abweichungen von dem von der Mehrheit definierten unmarkierten Normalfall wird eine Differenzordnung (Mecheril/Melter 2012) hergestellt, die das vermeintliche Anders-Sein ins Zentrum der Aufmerksamkeit rückt. Folgen sind Abwertung bestimmter (Erst-)Sprachen, Unterwerfung durch Beschreibungspraxen und Restriktionen auf dem Feld der Repräsentation (Broden/Mecheril 2007).
Ausgehend von diesen Überlegungen wird in der Arbeit „Ethnizität“ diskutiert, worauf viele dieser Bezeichnungen rekurrieren. Barth (1969, 1994) stellt fest, dass Ethnizität der Abgrenzung dient und Zugehörigkeit zu ethnische Gruppen durch kategoriale Selbst- und Fremdzuschreibungen bestimmt wird. Brubaker (2004) folgert daher, dass „Gruppen“ nur in Form von Vorstellungen existieren, die Individuen davon haben und diese Subjektivität zu unterschiedlichen Konstruktionen ethnischer Identität führt. Dementsprechend können auch „multiple ethnische Identitäten“ (Keupp 2002) und „Hybriditäten“ (Foroutan 2013) das Ergebnis der individuellen Konstruktion sein, ohne dass diese Formen gemeinhin akzeptierte Bezeichnungen darstellen.
Um die individuelle Entstehung ethnischer Identität nachvollziehen zu können, werden in der Arbeit Spracherwerbsgeschichten analysiert, da verschiedene Studien nahelegen, dass das Sprechen einer Sprache in engem Zusammenhang zur Ethnizität steht. Ohm (2008) zeigt, dass Zweitsprachenerwerb mit Identitätsprozessen in einem wechselseitigen Bedingungsverhältnis steht. Giles/Bourhis/Taylor (1977: 326) zeigen anhand von Untersuchungen in mehrsprachigen Gebieten wie Quebec und Wales, dass Sprache enger mit ethnischer Identität verbunden ist als Nationalität oder „Kultur“. Rosenberg (2015) führt am Beispiel der ehemaligen UdSSR auf, dass das Sprechen einer Sprache gleichbedeutend mit dem Zugehörigkeit zu einer ethnischen „Gruppe“ war. Sprache greift auch als Ausschlusskriterium: Nur wer eine Sprache gut spricht, darf die damit verbundene Identität in Anspruch nehmen (Schroeder/Dollnick, 2013: 104).
Mithilfe der Methode des narrativen Interviews können Spracherwerbsgeschichten produziert, und individuelle kognitive Perspektiven und gesellschaftliche Prozesse aufgedeckt werden. In der Analyse können vier Wege der Entstehung ethnischer Identität unterschieden werden: I. Ethnizität als primäre und dauerhafte Dimension, II. Multiple ethnische Identität, III. Unmarkierte ethnische Identität, IV. Selbstbestimmtheit. So kommt die Untersuchung zu dem Schluss, dass Ethnische Identität bei „Menschen mit türkischem Migrationshintergrund“ durch individuelle Erfahrungen entsteht, sich verändern und Mehrfachzugehörigkeiten oder Hybriditäten zulassen kann. Dieses Ergebnis widerspricht dem alltäglichen Gebrauch bestimmter Begriffe und stellt damit gängige Bezeichnungsweisen und Differenzordnungen in Frage.
There Is No Return To Egypt
(2013)
Who are those Polish Jews, who in the wake of the Antizionist Campaign of the year 1968 left their home country and migrated to Israel? How do they, 40 years after these traumatic events, look back at their own history? Which development have they made in the Jewish State, a society torn by wars and inner political tensions? How do they live in Israel at the beginning of the 21st century? In the documentary There Is No Return To Egypt seven members of the Polish-Jewish migration cohort of the late 1960s, early 1970s and there todays environment are represented. These people, while being on camera in their mid-fifties till late seventies of age, allow an intimate view into their Israeli-Polish daily-life and into their world of memories. Interestingly, having survived the atrocities of the Shoah and being forced out of Poland some twenty years later, the older interviewees draw their very own conclusions for their further lives in Israel. In contrast, the younger interviewees deal very differently with the loss of their home and the break in their career life caused by the Antizionist Campaign. The personalities presented in this documentary have various professions: There is a successful musician, a former employee at the Israeli broadcasting service, and there are skilled workers. Their religious identities widely vary: from Jewish orthodox and national-religious to atheist to Judeo-Christian. The protagonists in There Is No Return To Egypt do also represent the political spectrum of Israel: from members of the chauvinist-militarist camp through to members of the peace movement. At the same time, the shooting locations in the documentary are important stages of life for the seven 1968ers: the home being decorated for Shabbat or for Israels national holiday Yom ha-atzmaut, the working place, an army museum, a Jewish settlement in the Palestinian Westbank, a Shoah memorial event at the university campus, a pop concert and a peace demonstration.
Our understanding of the impact of climate-driven environmental change on prehistoric human populations is hampered by the scarcity of continuous paleoenvironmental records in the vicinity of archaeological sites. Here we compare a continuous paleoclimatic record of the last 20 ka before present from the Chew Bahir basin, southwest Ethiopia, with the available archaeological record of human presence in the region. The correlation of this record with orbitally-driven insolation variations suggests a complex nonlinear response of the environment to climate forcing, reflected in several long-term and short-term transitions between wet and dry conditions, resulting in abrupt changes between favorable and unfavorable living conditions for humans. Correlating the archaeological record in the surrounding region of the Chew Bahir basin, presumably including montane and lake-marginal refugia for human populations, with our climate record suggests a complex interplay between humans and their environment during the last 20 ka. The result may contribute to our understanding of how a dynamic environment may have impacted the adaptation and dispersal of early humans in eastern Africa. (C) 2015 Elsevier Ltd. All rights reserved.
This chapter focuses on the relationship between public opinion on migration and its media coverage. Different explanatory models, including individual characteristics, cultural factors and the impact of media and politics, have been proposed to explain public attitudes towards migrants. Understanding the local context is important, as the shares of migrants living in each region and city vary considerably. Providing correct statistical information, stressing the diversity of current migration patterns in Europe and taking part in media and public discussions are ways in which to impact public attitudes at the local level.
Integration von Zuwanderern
(2023)
Dieses Kapitel befasst sich mit der Beziehung zwischen der öffentlichen Meinung zur Migration und der Medienberichterstattung darüber. Verschiedene Erklärungsmodelle, darunter individuelle Merkmale, kulturelle Faktoren und der Einfluss von Medien und Politik, wurden vorgeschlagen, um die Einstellung der Öffentlichkeit gegenüber Migranten zu erklären. Es ist wichtig, den lokalen Kontext zu verstehen, da der Anteil der in den einzelnen Regionen und Städten lebenden Migranten sehr unterschiedlich ist. Die Bereitstellung korrekter statistischer Informationen, die Hervorhebung der Vielfalt der aktuellen Migrationsmuster in Europa und die Teilnahme an Medien- und öffentlichen Diskussionen sind Möglichkeiten, um die öffentliche Meinung auf lokaler Ebene zu beeinflussen.
In this introductory chapter, the editors describe the main theoretical basis of analysis of this book and the methodological approach. The core of this book consists of 14 country-specific chapters, which allow a European comparison and show the increasing variance in migration policy approaches within and between European countries. The degree of local autonomy, the level of centralisation and the traditional forms of migration policy are factors that especially influence the possibilities for local authorities to formulate their own integration policies.
In diesem einleitenden Kapitel beschreiben die Herausgeber die wichtigsten theoretischen Grundlagen der Analyse dieses Buches und den methodischen Ansatz. Der Kern des Buches besteht aus 14 länderspezifischen Kapiteln, die einen europäischen Vergleich ermöglichen und die zunehmende Varianz der migrationspolitischen Ansätze innerhalb und zwischen den europäischen Ländern aufzeigen. Der Grad der lokalen Autonomie, der Grad der Zentralisierung und die traditionellen Formen der Migrationspolitik sind Faktoren, die insbesondere die Möglichkeiten der lokalen Behörden beeinflussen, ihre eigene Integrationspolitik zu formulieren.
Bats are top insect predators on farmland, yet they suffer from intensive farmland management. Here, we evaluated the seasonal activity patterns of European bats above large, arable fields and compared these patterns between ecologically distinct bat species. Using repeated passive acoustic monitoring on a total of 93 arable fields in 2 years in Brandenburg, Germany, we surveyed the activity of different bat species between early spring and autumn. We then used generalized additive mixed models to describe and compare the seasonal bat activity patterns between bat categories, which were build based on the affiliation to a functional group and migratory class, while controlling for local weather conditions. In general, the affiliation to a bat category in interaction with the season in addition to cloud cover and ambient air temperature explained a major part of bat activity. The season was also an important factor for the foraging activity of open-space specialists such as Nyctalus noctula but showed only a weak effect on species such as Pipistreilus nathusii which are adapted to edge-space habitats. Across the seasons, habitat use intensity was high during the period of swarming and migration and low during the energy demanding period of lactation. Seasonal patterns in foraging activity showed that open-space specialists foraged more intensively above agricultural fields during the migration period, while edge-space specialists foraged also during the energy demanding period of lactation. We conclude that the significant seasonal fluctuations in bat activity and significant differences between bat categories in open agricultural landscapes should be taken into consideration when designing monitoring schemes and management plans for bat species in regions dominated by agriculture. Also, management plans should be directed to improve the conditions on arable land especially for bat species which would be classified as narrow-space foragers such as Myotis species. (C) 2016 Elsevier B.V. All rights reserved.
Myriam Yardeni a consacré des travaux à l'histoire de la Réforme, à la pensée politique et à l'historiographie des Huguenots, aux changements d'attitude envers le peuple juif, à l'Église du Désert, mais aussi au Refuge en Allemagne et en particulier en Prusse. Sans pouvoir retracer ici toute cette partie de son itinéraire de recherche, ni même étudier à fond ses contributions majeures à la recherche sur le Refuge en Prusse, ce texte ne veut qu'apporter un témoignage sur la vitalité et la productivité de sa méthode de recherche.
Migration is not a new phenomenon. However, recent data indicate that unprecedented numbers of people have experienced forced migration around the world with 51% under the age of 18 years. How can educational policies and practices respond sensitively to increasing cultural and migration-based diversity? The purpose of this special section that includes eight studies is to consider these issues more deeply. As a frame for the special section, we address the main question: What are promotive or protective factors for positive development of children and youth attending culturally diverse school contexts? In the collection of papers, these promotive and protective factors range from peers and families, to teachers, to organisational context and climate. With continued disruptions in children's lives due to a pandemic, climate change, war, conflict and poverty, migration will remain a pressing concern and will continue to transform the student populations in our classrooms and schools for the foreseeable future. The need to address how we can best provide students from diverse backgrounds equitable and supportive education, continues.
Being perceived as a foreigner regardless of one's generational status, citizenship, or self-identification is called foreigner objectification. This is a form of identity denial and is linked to psychological distress. To test how foreigner objectification could be measured in Europe, we assessed whether the Foreigner Objectification Scale demonstrated reliability and validity with German adolescents. The sample included 806 9th graders from 17 high schools. The results showed that the scale demonstrates good reliability, scalar measurement invariance across gender and citizenship status, and partial scalar measurement invariance across family heritage, generational status, and cultural self-identification. Adolescents who scored higher on the scale also reported greater school behavioral disengagement, lower life satisfaction, and stronger ethnic identity. Our findings suggest that the scale is psychometrically sound and is linked in theoretically consistent ways to adjustment and ethnic identity. We conclude that this scale offers another way to capture subtle discrimination experiences that add to a more comprehensive understanding of discrimination and the related implications in Europe.
Poverty and social exclusion are closely related to an increased risk for the deterioration of mental health. In 2018 approximately 19% of the German population were threatened by poverty and the associated social ostracization. Migrant groups in particular often show an increased risk for poverty and are often exposed to multiple socioeconomic stress factors depending on the context of migration, pre-migration and post-migration social factors. Numerous studies have shown that societal exclusion, precarious living conditions and the residential environment negatively affect mental health beyond the effects of pre-migration risk factors. This article provides a review and discussion on the relationship between mental health, poverty and related constructs, such as social cohesion, social capital and social exclusion in general as well as in specific risk groups, such as migrant and refugee populations.
Armed conflicts trigger region-specific mechanisms that affect land use change. Deforestation is presented as one of the most common negative environmental impacts resulting from armed conflicts, with relevant consequences in terms of greenhouse gas emissions and loss of ecosystem services. However, the impact of armed conflict on forests is complex and may simultaneously lead to positive and negative environmental outcomes, i.e. forest regrowth and deforestation, in different regions even within a country. We investigate the impact that armed conflict exerted over forest dynamics at different spatial scales in Colombia and for the global tropics during the period 1992–2015. Through the analysis of its internally displaced population (departures) our results suggest that, albeit finding forest regrowth in some municipalities, the Colombian conflict predominantly exerted a negative impact on its forests. A further examination of georeferenced fighting locations in Colombia and across the globe shows that conflict areas were 8 and 4 times more likely to undergo deforestation, respectively, in the following years in relation to average deforestation rates. This study represents a municipality level, long-term spatial analysis of the diverging effects the Colombian conflict exerted over its forest dynamics over two distinct periods of increasing and decreasing conflict intensity. Moreover, it presents the first quantified estimate of conflict's negative impact on forest ecosystems across the globe. The relationship between armed conflict and land use change is of global relevance given the recent increase of armed conflicts across the world and the importance of a possible exacerbation of armed conflicts and migration as climate change impacts increase.
The interaction between endothelial cells and pericytes is crucial for the stabilization of newly formed vessels in angiogenesis. The comprehension of the mechanisms regulating peiicyte recruitment might open therapeutical perspectives on vascular-related pathologies. Sphingosine 1phosphate (SIP) is a bioactive sphingolipid that derives from sphingomyelin catabolism and regulates biological functions in cell survival, proliferation, and differentiation. In this study, we aimed to identify the role of SIP axis in the intercellular communication between human mesenchymal progenitor mesoangioblasts (MAB) and endothelial cells (human microvascular endothelial cells (HMVEC)) in the formation of capillary-like structures. We demonstrated that the SIP biosynthetic pathway brought about by sphingosine kinases (SK) SKI and SK2 as well as spinster homolog 2 (SPNS2) transporter in H-MVEC is crucial for MAB migration measured by Boyden chambers and for the formation and stabilization of capillary-like structures in a 3D Matrigel culture. Moreover, the conditioned medium (CM) harvested from HMVEC, where SKI, 5K2, and SPNS2 were down-regulated, exerted a significantly diminished effect on MAB capillary morphogenesis and migration. Notably, we demonstrated that S I Pi and Si p3 receptors were positively involved in CM-induced capillary-like formation and migration, while S I P2 exerted a negative role on CM-induced migratory action of MAB. Finally, SK inhibition as well as MAB SlPi and S1P3 down-regulation impaired HMVEC-MAB cross-talk significantly reducing in vivo angiogenesis evaluated by Matrigel plug assay. These findings individuate novel targets for the employment of MAB in vascular-related pathologic conditions.
Organizing immigration
(2020)
Immigration constitutes a dynamic policy field with – often quite unpredictable – dynamics. This is based on immigration constituting a ‘wicked problem’ meaning that it is characterized by uncertainty, ambiguity and complexity. Due to the dynamics in the policy field, expectations towards public administrations often change. Following neo-institutionalist theory, public administrations depend on meeting the expectations in the organizational field in order to maintain legitimacy as the basis for, e.g., resources and compliance of stakeholders. With the dynamics in the policy field, expectations might change and public administrations consequently need to adapt in order to maintain or repair the then threatened legitimacy. If their organizational legitimacy is threatened by a perception of structures and processes being inadequate for changed expectations, an ‘institutional crisis’ unfolds. However, we know little about ministerial bureaucracies’ structural reactions to such crucial momentums and how this effects the quest for coordination within policy-making. Overall, the dissertation thus links to both policy analysis and public administration research and consists of five publications. It asks: How do structures in ministerial bureaucracies change in the context of institutional crises? And what effect do these changes have on ministerial coordination? The dissertation hereby focusses on the above described dynamic policy field of immigration in Germany in the period from 2005 to 2017 and pursues three objectives: 1) to identify the context and impulse for changes in the structures of ministerial bureaucracies, 2) to describe respective changes with regard to their organizational structures, and 3) to identify their effect on coordination. It hereby compares and contrasts institutional crises by incremental change and shock as well as changes and effects at federal and Länder level which allows a comprehensive answer to both of the research questions. Theoretically, the dissertation follows neo-institutionalist theory with a particular focus on changes in organizational structures, coordination and crisis management. Methodologically, it follows a comparative design. Each article (except for the literature review), focusses on ministerial bureaucracies at one governmental level (federal or Länder) and on an institutional crisis induced by either an incremental process or a shock. Thus, responses and effects can be compared and contrasted across impulses for institutional crises and governmental levels. Overall, the dissertation follows a mixed methods approach with a majority of qualitative single and small-n case studies based on document analysis and semi-structured interviews. Additionally, two articles use quantitative methods as they best suited the respective research question. The rather explorative nature of these two articles however fits to the overall interpretivist approach of the dissertation. Overall, the dissertation’s core argument is: Within the investigation period, varying dynamics and thus impulses for institutional crises took place in the German policy field of immigration. Respectively, expectations by stakeholders on how the politico-administrative system should address the policy problem changed. Ministerial administrations at both the federal and Länder level adapted to these expectations in order to maintain, or regain respectively, organizational legitimacy. The administration hereby referred to well-known recipes of structural changes. Institutional crises do not constitute fields of experimentation. The new structures had an immediate effect on ministerial coordination, with respect to both the horizontal and vertical dimension. Yet, they did not mean a comprehensive change of the system in place. The dissertation thus challenges the idea of the toppling effect of crises and rather shows that adaptability and persistence of public administrations constitute two sides of the same coin.
Großstädte sind in den letzten Jahrzehnten einem massiven wirtschaftlichen und gesellschaftlichen Wandel ausgesetzt, der die städtische Sozialstruktur einmal mehr entscheidend veränderte. Basierend auf Erkenntnissen der Stadtsoziologie sowie der Arbeitsmarkt- und Migrationsforschung untersucht der vorliegende Beitrag diese Entwicklung am Beispiel Wiens. Dabei wird insbesondere der These einer zunehmenden sozialen Polarisierung in Städten nachgegangen. Es zeigt sich, dass auch in Wien die Mittelschichten im letzten Vierteljahrhundert geschrumpft sind. Ergebnisse aus multinomialen logistischen Regressionsmodellen und Dekompositionsanalysen weisen zudem darauf hin, dass Veränderungen am Arbeitsmarkt (z. B. zunehmende Verbreitung von Teilzeit) und in der Bevölkerungszusammensetzung (z. B. Herkunft von Zuwanderern) zu diesem Wandel beigetragen haben, während das steigende Bildungsniveau der Stadtbevölkerung ein noch stärkeres Schrumpfen der Mittelschicht verhindert hat.
One of the tremendous discoveries by the Cassini spacecraft has been the detection of propeller structures in Saturn's A ring. Although the generating moonlet is too small to be resolved by the cameras aboard Cassini, its produced density structure within the rings, caused by its gravity can be well observed. The largest observed propeller is called Blériot and has an azimuthal extent over several thousand kilometers. Thanks to its large size, Blériot could be identified in different images over a time span of over 10 years, allowing the reconstruction of its orbital evolution. It turns out that Blériot deviates considerably from its expected Keplerian orbit in azimuthal direction by several thousand kilometers. This excess motion can be well reconstructed by a superposition of three harmonics, and therefore resembles the typical fingerprint of a resonantly perturbed body. This PhD thesis is directed to the excess motion of Blériot. Resonant perturbations are a known for some of the outer satellites of Saturn. Thus, in the first part of this thesis, we seek for suiting resonance candidates nearby the propeller, which might explain the observed periods and amplitudes. In numeric simulations, we show that indeed resonances by Prometheus, Pandora and Mimas can explain the libration periods in good agreement, but not the amplitudes. The amplitude problem is solved by the introduction of a propeller-moonlet interaction model, where we assume a broken symmetry of the propeller by a small displacement of the moonlet. This results in a librating motion the moonlet around the propeller's symmetry center due to the non-vanishing accelerations. The retardation of the reaction of the propeller structure to the motion of the moonlet causes the propeller to become asymmetric. Hydrodynamic simulations to test our analytical model confirm our predictions. In the second part of this thesis, we consider a stochastic migration of the moonlet, which is an alternative hypothesis to explain the observed excess motion of Blériot. The mean-longitude is a time-integrated quantity and thus introduces a correlation between the independent kicks of a random walk, smoothing the noise and thus makes the residual look similar to the observed one for Blériot. We apply a diagonalization test to decorrelated the observed residuals for the propellers Blériot and Earhart and the ring-moon Daphnis. It turns out that the decorrelated distributions do not strictly follow the expected Gaussian distribution. The decorrelation method fails to distinguish a correlated random walk from a noisy libration and thus we provide an alternative study. Assuming the three-harmonic fit to be a valid representation of the excess motion for Blériot, independently from its origin, we test the likelihood that this excess motion can be created by a random walk. It turns out that a non-correlated and correlated random walk is unlikely to explain the observed excess motion.
Measuring migration 2.0
(2021)
The interest in human migration is at its all-time high, yet data to measure migration is notoriously limited. “Big data” or “digital trace data” have emerged as new sources of migration measurement complementing ‘traditional’ census, administrative and survey data. This paper reviews the strengths and weaknesses of eight novel, digital data sources along five domains: reliability, validity, scope, access and ethics. The review highlights the opportunities for migration scholars but also stresses the ethical and empirical challenges. This review intends to be of service to researchers and policy analysts alike and help them navigate this new and increasingly complex field.
In response to mounting evidence on the dangers of irregular migration from Africa to Europe, the number of information campaigns which aim to raise awareness about the potential risks has rapidly increased. Governments, international organizations and civil society organizations implement a variety of campaigns to counter the spread of misinformation accelerated by smuggling and trafficking networks. The evidence on the effects of such information interventions on potential migrants remains limited and largely anecdotal. More generally, the role of risk perceptions in the decision-making process of potential irregular migrants is rarely explicitly tested, despite the fact that the concept of risk pervades conventional migration models, particularly in the field of economics. We address this gap by assessing the effects of a peer-to-peer information intervention on the perceptions, knowledge and intentions of potential migrants in Dakar, Senegal, using a randomized controlled trial design. The results show that - three months after the intervention - peer-to-peer information events increase potential migrants' subjective information levels, raise risk awareness, and reduce intentions to migrate irregularly. We find no substantial effects on factual migration knowledge. We discuss how the effects may be driven by the trust and identification-enhancing nature of peer-to-peer communication. <br /> (c) 2021 Elsevier Ltd. All rights reserved.
This edited volume examines entanglements and disentanglements between Africa and East Germany during and after the Cold War from a global history perspective. Extending the view beyond political elites, it asks for the negotiated and plural character of socialism in these encounters and sheds light on migration, media, development, and solidarity through personal and institutional agency. With its distinctive focus on moorings and unmoorings, the volume shows how the encounters, albeit often brief, significantly influenced both African and East German histories.