La motilité cellulaire directionnelle au cours du développement de l'organisme et des tissus, l'homéostasie et la maladie nécessite une rupture de symétrie. Ce processus repose sur la capacité des cellules individuelles à établir une polarité avant-arrière, et peut se produire en l'absence de signaux externes. L'initiation de la migration a été attribuée à la polarisation spontanée des composants du cytosquelette, tandis que l'évolution spatio-temporelle des forces du cytosquelette résultant de l'interaction mécanique cellule-substrat continue n'a pas encore été résolue. Ici, nous établissons un test de migration microfabriqué unidimensionnel qui imite un environnement fibrillaire complexe in vivo tout en étant compatible avec les mesures de force à haute résolution, la microscopie quantitative et l'optogénétique. La quantification des paramètres morphométriques et mécaniques révèle un comportement de stick-slip générique initié par un détachement stochastique des contacts adhésifs d'un côté de la cellule dépendant de la contractilité, qui est suffisant pour conduire la motilité cellulaire directionnelle en absence de polarité du cytosquelette préétablie ou de gradients morphogènes. Un modèle théorique valide le rôle crucial de la dynamique d'adhésion au cours de la rupture de symétrie spontanée, en proposant que le phénomène examiné puisse émerger indépendamment d'un système auto-polarisant complexe. / Directional cell motility during organism and tissue development, homeostasis and disease requires symmetry breaking. This process relies on the ability of single cells to establish a front-rear polarity, and can occur in absence of external cues. The initiation of migration has been attributed to the spontaneous polarization of cytoskeleton components, while the spatio- temporal evolution of cytoskeletal forces arising from continuous mechanical cell-substrate interaction has yet to be resolved. Here, we establish a one- dimensional microfabricated migration assay that mimics complex in vivo fibrillar environment while being compatible with high-resolution force measurements, quantitative microscopy, and optogenetics. Quantification of morphometric and mechanical parameters reveals a generic stick-slip behavior initiated by contractility-dependent stochastic detachment of adhesive contacts at one side of the cell, which is sufficient to drive directional cell motility in absence of pre-established cytoskeleton polarity or morphogen gradients. A theoretical model validates the crucial role of adhesion dynamics during spontaneous symmetry breaking, proposing that the examined phenomenon can emerge independently of a complex self-polarizing system.

Abstract While Niue’s resident population is below 1,500, New Zealand’s Niuean population now exceeds 22,000. The vast and recent out-migration is resulting in many changes to on-island Niuean society and culture. Much research on Polynesian migration focuses on out-migrants and their new place of living, especially in relation to Tongan and Samoan migration. While drawing on the theoretical insights of previous research, this thesis focuses on the less researched Polynesian nation of Niue as the cultural homeland of Niuean out-migrants, to investigate how their on-island culture is changing as a result of the significant out-migration of its residents that began in the late 1960s. It uses the analytical lens of culture and migration to understand in greater detail the social and cultural changes in Niue by the contemporary migration. Using ethnographic field research the thesis examines and analyses the impact of ‘cultural migration’ in relation to the central aspects of on-island Niuean social and cultural change, ranging from everyday life occurrences to once in a lifetime events. The thesis examines changes involving such items as language, Niuean youth haircutting and ear-piercing ceremonies, food habits, Niuean entertainment, arts and crafts, family and more. From ethnographic data collected in Niue and among the out-migrant Niuean community in New Zealand, the thesis argues that on-island Niueans are taking on the characteristics of out-migrant Niueans. Although New Zealand administered Niue for many years and still has a role in Niue’s status as a Pacific island-nation, Niueans themselves have been most responsible for the changes influencing their on-island society and culture.

<p>Animal migration is a well known natural phenomenon and bird migration is perhaps the most obvious type. In some bird populations all individuals migrate, while in others only a fraction of the population migrates. The blue tit is a partial migrant; i.e. some individuals in the population migrate while others are sedentary. Some years, large numbers of partial migrants leave their breeding grounds and appear as invasion species in other areas. Shortage of food and high population densities are suggested as two important releasing factors. Theory predicts that juvenile birds, especially females, should arrive earlier since they are smaller and therefore are forced to leave their birth areas first.</p><p>In this study, the migration of blue tits at Hammarö Bird Observatory in northern lake Vänern (HBO) was examined with respect to age and sex distribution. During the autumns of 1977-2005, a total number of 13 944 blue tits were caught and ringed at HBO. A large fraction of the caught blue tits were juveniles, of which female and non-sexed birds dominated. Juvenile males were the third largest group, whereas adults were only caught in small numbers. The period when most birds arrived was between 28th of September and 2nd of October, but juvenile females did not arrived significantly earlier. The median arrival date was the 2nd of October, and the mean arrival date was 30th of September. There was a trend of earlier arrival dates, which may be due to warmer spring climate leading to an earlier breeding start. Analyses showed that the proportion of juveniles increased significantly with mean arrival date and total number of birds caught. Comparison between HBO, Falsterbo and Ottenby showed that birds arrived significantly earlier at HBO. In 1990 and 2003 all bird observatories (HBO, Falsterbo, Ottenby and Jomfruland) captured more birds than respectively stations average and in 1995, 1998 and 2002 fewer birds than average were captured at all sites.</p> / <p>Förekomsten av migration är vida känt i djurvärlden och fåglars flyttning är kanske den mest uppenbara typen. I vissa populationer flyttar alla fåglar, i andra flyttar ingen. Blåmesen tillämpar partiell migration, dvs. en del individer i populationen flyttar medan andra stannar. Vissa år lämnar partiellt flyttande fåglar fortplantningsområdet i stora antal och invaderar andra områden – dålig födotillgång och höga populationstätheter är två viktiga, utlösande faktorer.</p><p>I den här studien undersöktes successionen av flyttande blåmesar vid Hammarö fågelstation i norra delen av Vänern (HBO) med avseende på ålders- och könsfördelning. Under höstarna 1977-2005 fångades och ringmärktes totalt 13 944 blåmesar vid HBO. Den största delen av de fångade blåmesarna var ungfåglar, av vilka honor och obestämda fåglar dominerade. Juvenila hanar utgjorde den tredje största gruppen, medan de adulta fåglarna var få. Den period då de flesta fåglarna fångades var 28 september till 2 oktober. Mediandatum för fångst var 2 oktober, medan medeldatumet var 30 september. Tvärtemot förutsägelserna anlände inte juvenila honor signifikant tidigare än andra kategorier. Det finns en trend att fåglarna fångas allt tidigare på hösten, vilket kan vara ett resultat av ett varmare vårklimat med tidigarelagd häckning som följd. Regressioner visade att proportionen juvenila fåglar ökade signifikant med medelankomstdatum och med det totala antalet fångade fåglar. En jämförelse mellan HBO, Falsterbo och Ottenby visade att fåglarna anlände signifikant tidigare till HBO. 1990 och 2003 var de enda år då HBO, Falsterbo, Ottenby och Jomfruland fångade fler fåglar än respektive stations medelvärde. Åren 1995, 1998 och 2002 fångades färre fåglar än medelvärdet på samtliga stationer.</p>

Die Grenze - historisches Auslaufmodell? Moralische Zumutung? Unabdingbare Tatsache? Meist ist sie eine Art Limes: Durchlässig für den Austausch bestimmter Waren und Personen, zugleich Schutz gegen das Eindringen unerwünschter Fremder. Vielfach erklärtes Ziel ist ein "grenzenloses Europa". Im Innern der EU sind Schlagbäume verschwunden, an den Rändern wird vielerorts abgeschottet. Die Grenzsortierungen der EU sind Thema der aktuellen WeltTrends. Afghanistan und kein Ende? Die Londoner Konferenz verspricht trotz "neuer Strategie" keinen erfolgreichen Neuanfang. "Es wird zunächst schlimmer", so ein hoher deutscher Militär. Alternativen müssen diskutiert werden: WeltTrends bietet den Raum.

Die vorliegende Arbeit befasst sich mit der Untersuchung von Wanderungsüberlegungen der Einwohner der Stadt Visaginas vor dem Hintergrund steigender ökonomischer Unsicherheit, bedingt durch die bevorstehende Schließung des Atomkraftwerkes &#39;Ignalina&#39;.<br><br> Visaginas befindet sich im Nordosten Litauens, in einer der strukturschwächsten Regionen des Landes. Von Mitte der 70er bis Ende der 80er Jahre entstand die Stadt als Wohnstätte für die Arbeiter des sich zu dieser Zeit ebenfalls im Bau befindlichen Atomkraftwerkes &#39;Ignalina&#39; sowie für deren Angehörige. Noch heute ist die Stadt wirtschaftlich vom Kraftwerk abhängig: Nicht nur ist das staatliche Unternehmen der größte Arbeitgeber für die ca. 30.000 Einwohner, sondern darüber hinaus stellt auch die Mehrzahl der unabhängigen Firmen ihre Leistungen und Produktion in dessen Dienst. <br>Auf Druck der Europäischen Union, welche bereits Ende der 90er Jahre aus sicherheitstechnischen Gründen die Schließung des Atomkraftwerkes forderte, beschloss die Regierung Litauens, das Atomkraftwerk stillzulegen. Am 1. Januar 2005 wird der Betrieb des ersten Reaktors eingestellt. Die endgültige Abschaltung ist bis zum Januar 2009 vorgesehen. Auf diese Weise wird der Stadt Visaginas, und damit verbunden vielen ihrer Einwohner, die wirtschaftliche Existenzgrundlage entzogen. Bedingt durch den Wegfall ihres Arbeitsplatzes wird ein Großteil der Einwohner gezwungen sein, sich nach Beschäftigungsalternativen umzuschauen. Da jedoch auch im Umland der Stadt keine ausreichenden Möglichkeiten bestehen, die freigesetzten Arbeitskräfte aufzufangen, wird für viele Betroffene die einzige Alternative darin liegen, Visaginas auf der Suche nach einem neuen Arbeitsplatz zu verlassen. Die Tatsache, dass der Großteil der heutigen Einwohner aus anderen Unionsrepubliken der damaligen Sowjetunion nach Visaginas kam und nur selten über gute Kenntnisse in der Landessprache Litauisch verfügt, stellt dabei ein besonderes Problem dar.<br> Der Arbeit lag folgende zentrale Fragestellung zugrunde: Warum wandern unter gleichen strukturellen (vor allem ökonomischen) Rahmenbedingungen Menschen aus Visaginas ab, während andere dies nicht tun bzw. eine Abwanderung gar nicht in Erwägung ziehen?<br><br> Betreuer/Gutachter: Prof. Wilfried Heller; Prof. Sebastian Lentz

Animal migration is a well known natural phenomenon and bird migration is perhaps the most obvious type. In some bird populations all individuals migrate, while in others only a fraction of the population migrates. The blue tit is a partial migrant; i.e. some individuals in the population migrate while others are sedentary. Some years, large numbers of partial migrants leave their breeding grounds and appear as invasion species in other areas. Shortage of food and high population densities are suggested as two important releasing factors. Theory predicts that juvenile birds, especially females, should arrive earlier since they are smaller and therefore are forced to leave their birth areas first. In this study, the migration of blue tits at Hammarö Bird Observatory in northern lake Vänern (HBO) was examined with respect to age and sex distribution. During the autumns of 1977-2005, a total number of 13 944 blue tits were caught and ringed at HBO. A large fraction of the caught blue tits were juveniles, of which female and non-sexed birds dominated. Juvenile males were the third largest group, whereas adults were only caught in small numbers. The period when most birds arrived was between 28th of September and 2nd of October, but juvenile females did not arrived significantly earlier. The median arrival date was the 2nd of October, and the mean arrival date was 30th of September. There was a trend of earlier arrival dates, which may be due to warmer spring climate leading to an earlier breeding start. Analyses showed that the proportion of juveniles increased significantly with mean arrival date and total number of birds caught. Comparison between HBO, Falsterbo and Ottenby showed that birds arrived significantly earlier at HBO. In 1990 and 2003 all bird observatories (HBO, Falsterbo, Ottenby and Jomfruland) captured more birds than respectively stations average and in 1995, 1998 and 2002 fewer birds than average were captured at all sites. / Förekomsten av migration är vida känt i djurvärlden och fåglars flyttning är kanske den mest uppenbara typen. I vissa populationer flyttar alla fåglar, i andra flyttar ingen. Blåmesen tillämpar partiell migration, dvs. en del individer i populationen flyttar medan andra stannar. Vissa år lämnar partiellt flyttande fåglar fortplantningsområdet i stora antal och invaderar andra områden – dålig födotillgång och höga populationstätheter är två viktiga, utlösande faktorer. I den här studien undersöktes successionen av flyttande blåmesar vid Hammarö fågelstation i norra delen av Vänern (HBO) med avseende på ålders- och könsfördelning. Under höstarna 1977-2005 fångades och ringmärktes totalt 13 944 blåmesar vid HBO. Den största delen av de fångade blåmesarna var ungfåglar, av vilka honor och obestämda fåglar dominerade. Juvenila hanar utgjorde den tredje största gruppen, medan de adulta fåglarna var få. Den period då de flesta fåglarna fångades var 28 september till 2 oktober. Mediandatum för fångst var 2 oktober, medan medeldatumet var 30 september. Tvärtemot förutsägelserna anlände inte juvenila honor signifikant tidigare än andra kategorier. Det finns en trend att fåglarna fångas allt tidigare på hösten, vilket kan vara ett resultat av ett varmare vårklimat med tidigarelagd häckning som följd. Regressioner visade att proportionen juvenila fåglar ökade signifikant med medelankomstdatum och med det totala antalet fångade fåglar. En jämförelse mellan HBO, Falsterbo och Ottenby visade att fåglarna anlände signifikant tidigare till HBO. 1990 och 2003 var de enda år då HBO, Falsterbo, Ottenby och Jomfruland fångade fler fåglar än respektive stations medelvärde. Åren 1995, 1998 och 2002 fångades färre fåglar än medelvärdet på samtliga stationer.

The purpose of this project is to help a growing company reform their static information system to a dynamic system compatible with growth. The solution consists of migrating the legacy system that they have in FileMaker to an open technology platform. To solve this specific problem “patterns” have been used and this project explains these general solution “patterns”. We understand patterns like a generic solution to persistent design problems. General solutions will not only be useful in this specific problem, but they will be useful in all kind of similar migration projects as well. This thesis gives a detailed explanation of how to apply these patterns into the AEMI specific problem and how they can be useful in the migration process. The solution of the problem then, is following the advice of “patterns” to achieve our goals; these goals are the requirements that are given from the company supervisor. After the migration process a redesign process must be done in order to organize the information. This redesign consists of organizing the migrated information as well as adding the new information in the correct place. This thesis focuses on the process of migrating from a legacy system to a MySQL system through the use of the generic solution called “patterns”.  The final result is a MySQL database with all the old and new information together in a more adaptable platform for the company’s scalability.

This thesis in Global Development has looked at the personal experiences of non-European medical doctors that have migrated to Sweden to find out what they have encountered during the process of trying to obtain a Swedish medical license and if there are signs of discrimination. Sweden has a shortage of doctors, but has not resorted to brain drain. Contrary, it is difficult for non-European doctors to work as doctors in Sweden. This thesis has used a qualitative research strategy and five non-European unemployed doctors that were trying to get Swedish medical licenses as well as one non-European doctor that was working, were interviewed. Empirical data from a seminar with Swedish doctors about the pro-cess that foreign doctors have to go through to be able to work in Sweden has also been used in this thesis. The results showed that doctors from non-European countries have stricter requirements to fulfill in order to be able to practice medicine in Sweden than doctors coming from European countries. The system for accepting foreign doctors and validating their competence was flawed. The pro-cess was confusing, frustrating and unnecessarily long. Although there was no direct discrimina-tion or prejudice, European doctors were favored by the system. / Denna C-uppsats i Global Utveckling har tittat på personliga erfarenheter av icke-europeiska läkare som har migrerat till Sverige för att ta reda på vad de har stött på under processen av att skaffa svensk läkarlegitimation och om det finns tecken på diskriminering. Sverige har brist på läkare, men har inte tillgripit ”brain drain”. Tvärtemot är det svårt för icke-europeiska läkare att arbeta som läkare i Sverige. En kvalitativ forskningsstrategi har använts och fem icke-europeiska arbetslösa läkare som försökte få svenska läkarlegitimationer samt en icke-europeisk läkare som arbetade intervjuades. Empiriska data från ett seminarium med svenska läkare som handlade om processen som utländska läkare måste gå igenom för att kunna arbeta i Sverige har också använts i denna C-uppsats. Resultaten visade att läkare från icke-europeiska länder har strängare krav att uppfylla för att kunna arbeta som läkare i Sverige än läkare som kommer från europeiska länder. Systemet för att ta emot icke-europeiska läkare och validera deras kompetens var bristfällig. Processen var förvirrande, frustrerande och onödigt lång. Även om det inte fanns någon direkt diskriminering, så var europeiska läkare gynnade av systemet.

There seems to be a gap in previous literature where economists and social scientists do not focus on factors driving emigration of health professionals between developed coun-tries. Although, there is a lot of literature that discusses emigration of health profession-als from developing towards developed countries, there are few previous studies of health professional emigration between developed to developed countries. This paper examines and analyzes factors which might be of importance in determining the direc-tion of emigration of health professionals between developed countries. The concept of health professionals in our study contains people with more than 3 years of education within the health and social welfare sector, not referring to any particular occupation such as nurses, doctors, dentist etc; or whether they are specialized in any area. This pa-per analyses factors that affect emigration of Swedish health professionals, using eco-nomic and social variables in a structured regression model. The results indicate that the percentage of Swedish health professionals is directly affected by factors of destination countries such as geographical proximity, GDP(PPP) per capita, income tax rate and co-workers encouraging development.

<p>There seems to be a gap in previous literature where economists and social scientists do not focus on factors driving emigration of health professionals between developed coun-tries. Although, there is a lot of literature that discusses emigration of health profession-als from developing towards developed countries, there are few previous studies of health professional emigration between developed to developed countries. This paper examines and analyzes factors which might be of importance in determining the direc-tion of emigration of health professionals between developed countries. The concept of health professionals in our study contains people with more than 3 years of education within the health and social welfare sector, not referring to any particular occupation such as nurses, doctors, dentist etc; or whether they are specialized in any area. This pa-per analyses factors that affect emigration of Swedish health professionals, using eco-nomic and social variables in a structured regression model. The results indicate that the percentage of Swedish health professionals is directly affected by factors of destination countries such as geographical proximity, GDP(PPP) per capita, income tax rate and co-workers encouraging development.</p>