Hasil untuk "Colonies and colonization. Emigration and immigration. International migration"

Yi Liu, Hongda Zhang, Zhongxue Gan et al.

Ant Colony Optimization (ACO) is a prominent swarm intelligence algorithm extensively applied to path planning. However, traditional ACO methods often exhibit shortcomings, such as blind search behavior and slow convergence within complex environments. To address these challenges, this paper proposes the Pheromone-Focused Ant Colony Optimization (PFACO) algorithm, which introduces three key strategies to enhance the problem-solving ability of the ant colony. First, the initial pheromone distribution is concentrated in more promising regions based on the Euclidean distances of nodes to the start and end points, balancing the trade-off between exploration and exploitation. Second, promising solutions are reinforced during colony iterations to intensify pheromone deposition along high-quality paths, accelerating convergence while maintaining solution diversity. Third, a forward-looking mechanism is implemented to penalize redundant path turns, promoting smoother and more efficient solutions. These strategies collectively produce the focused pheromones to guide the ant colony's search, which enhances the global optimization capabilities of the PFACO algorithm, significantly improving convergence speed and solution quality across diverse optimization problems. The experimental results demonstrate that PFACO consistently outperforms comparative ACO algorithms in terms of convergence speed and solution quality.

Alassane Bah, Timothée Brochier

The North-West African coast is enriched by the Canary current, which sustain a very produc- tive marine ecosystem. The Senegalese artisanal fishing fleet, the largest in West Africa, ben- efit from this particularly productive ecosystem. It has survived the ages with remarkable adaptability, and has great flexibility allowing it to react quickly to changes, in particular by changing fishing gear and performing migrations. However, since the 1980s, the increasing fishing effort led to a progressive fish depletion, increasing fisher's migration distances to access new fishing grounds. Since 2007 many fishers even started to navigate to Canary archi- pelago in order to find a more lucrative job in Europe, carrying candidate to emigration in their canoes. This phenomenon further increased since 2022 due to a new drop in fishery yields, consecutive to the development of fishmeal factories along the coast that amplified overfishing. Climate change may also impact fish habitat, and by consequence the distribution of fishing grounds. The question addressed in this research was how climate change, fishing effort and socio-economic parameters interact and determine the artisanal fishery dynamics. An interdisciplinary approach allowed us to collect data and qualitative information on cli- mate, fishing effort and socio-economic parameters. This served as a basis to build a multi- agent model of the mobility of Senegalese artisanal fishing. We implemented a first version of the model and presented some preliminary simulations with contrasted fishing effort and climate scenario. The results suggested that first, climate change should have only a slight impact on artisanal fishing, even in the most extreme climate scenario considered. Second, if fishing effort was maintained at current levels, we found a collapse of the fishery with massive fishers migrations whatever the climate scenario. Third, with reduced fishing effort, a sustain- able fishery equilibrium emerges in which Senegal's artisanal fishery catches ~250,000 tons of fish a year mostly in Senegal, approaching the 2000s catches records. This sustainable equi- librium maintained with the two-climate change scenario tested. Fishers migrations provide clues of the fish populations state and have implications for the sustainable exploitation of fishing resources. Senegalese artisanal fishers' migrations impact the regional distribution of the fishing effort, therefore must be taken into account in regional development and planning policies for this sector, particularly in a context of increasing infrastructure and spatial man- agement measures (e.g. marine protected areas). This work lays the foundations of a computer simulation tool for decision support.

Sergio Micó-Rosa, Concepcion Garcia-Pardo, Matteo Frasson et al.

The dielectric characterization of human tissues can play a crucial role in the development of new medical diagnostic tools. In particular, the characterization of healthy and pathological tissues can provide vital information for diagnosis. In this paper, preliminary results from a small-scale measurement campaign conducted in 0.5-26.5GHz during real surgeries on healthy and malignant human colon tissues are presented. Those measurements were carried out externally to the colon, without direct contact to the tumor growing inside the colon. Furthermore, different tumor stages are taken into account. Initial findings reveal that advanced tumor stages are related with increased higher values of dielectric properties in malignant tumor tissues compared to the healthy ones.

Matthäus Siebenhofer, Pjotrs Žguns, Bilge Yildiz

Ion migration in WO$_3$ is a critical process for various technological applications, such as in batteries, electrochromic devices and energy-efficient brain-inspired computing devices. In this study, we investigate the migration mechanisms of H$^+$, Li$^+$, and Mg$^{2+}$ ions in monoclinic WO$_3$, and how energy barriers are affected by the presence of electron polarons and by lattice strain. Our approach in calculating the migration paths and barriers is based on density functional theory methods. The results show that the presence of polarons leads to association effects and lattice deformations that increase ion migration barriers. Therefore, the consideration of polarons is critical to accurately predict activation energies of ion migration. We further show that lattice strain modulates ion migration barriers, however, the impact of strain depends on the migrating ion. For protons that are embedded in the oxygen ion electronic shells and hop from donor to acceptor oxygens, compressive lattice strain accelerates migration by reducing the donor-acceptor distance. In contrast, the migration barriers of larger ions decrease with tensile lattice strain that increases the free space for the ion in the transition state. These insights into the effects of polarons and lattice strain are important for understanding and tuning properties of WO$_3$ when aiming for optimized device characteristics.

Mohayeminul Islam, Ajay Kumar Jha, May Mahmoud et al.

Library migration is the process of replacing a library with a similar one in a software project. Manual library migration is time consuming and error prone, as it requires developers to understand the Application Programming Interfaces (API) of both libraries, map equivalent APIs, and perform the necessary code transformations. Due to the difficulty of the library migration process, most of the existing automated techniques and tooling stop at the API mapping stage or support a limited set of libraries and code transformations. In this paper, we develop an end-to-end solution that can automatically migrate code between any arbitrary pair of Python libraries that provide similar functionality. Due to the promising capabilities of Large Language Models (LLMs) in code generation and transformation, we use LLMs as the primary engine for migration. Before building the tool, we first study the capabilities of LLMs for library migration on a benchmark of 321 real-world library migrations. We find that LLMs can effectively perform library migration, but some post-processing steps can further improve the performance. Based on this, we develop MigrateLib, a command line application that combines the power of LLMs, static analysis, and dynamic analysis to provide accurate library migration. We evaluate MigrateLib on 717 real-world Python applications that are not from our benchmark. We find that MigrateLib can migrate 32% of the migrations with complete correctness. Of the remaining migrations, only 14% of the migration-related changes are left for developers to fix for more than half of the projects.

Sucharita Giri

Technological advancements in generation of ultrafast and intense laser pulses have enabled the real-time observation and control of charge migration in molecules on their natural timescale, which ranges from few femtoseconds to several hundreds of attoseconds. Present thesis discusses the effect of symmetry on the adiabatic attosecond charge migration in different molecular systems. The spatial representation of the charge migration is documented by time-dependent electronic charge and flux densities. Furthermore, the induced charge migration is imaged via time resolved x-ray diffraction (TRXD) with atomic-scale spatiotemporal resolution in few cases.

Hailiang Li, Li-Yong Zhou, Xiaoping Zhang

Planetary migration is a crucial stage in the early solar system, explaining many observational phenomena and providing constraints on details related to the solar system's origins. This paper aims to investigate the acceleration during planetary migration in detail using numerical simulations, delving deeper into the early solar system's preserved information. We confirm that planetary migration is a positive feedback process: the faster the migration, the more efficient the consumption of planetesimals; once the migration slows down, Neptune clears the surrounding space, making further migration more difficult to sustain. Quantitatively, a tenfold increase in migration rate corresponds to an approximately 30% reduction in the mass of planetesimals consumed to increase per unit angular momentum of Neptune. We also find that Neptune's final position is correlated with the initial surface density of planetesimals at that location, suggesting that the disk density at 30au was approximately 0.009$M_{\oplus}/au^2$ in the early solar system. Two mechanisms that can accelerate planetary migration are identified: the first is MMR between Uranus and Neptune. Migration acceleration will be triggered whenever these two giant planets cross their major MMR. The second mechanism is the ring structure within the planetesimal disk, as the higher planetesimal density in this region can provide the material support necessary for migration acceleration. Our research indicates that Neptune in the current solar system occupies a relatively delicate position. In case Neptune crossed the 1:2 MMR with Uranus, it could have migrated to a much more distant location. Therefore, under the influence of the positive feedback mechanism, the evolution of the solar system to its current configuration might be a stochastic outcome rather than an inevitable consequence.

Arnak Sargsyan

This book comparatively analyzes various forms of populism in countries with democratic political systems and regimes. In various chapters, the authors draw attention to the common elements of populism that have already emerged: the desire for political representation, a charismatic leader, a nationalist idealization of the historical role of ‘the people’, criticism of the EU, the Council of Europe, the OSCE and international law. In this book, various authors point out that populist phenomena are used to destroy both the tools and the rules and culture of democracy. Most populist political parties gain widespread acceptance among young people because of their extreme views and statements, thereby calling for the abandonment of democratic principles, that is, the political order and the rule of law. In this book, the authors use an interdisciplinary approach to highlight the importance of political and social accountability and responsibility, examining the major challenges facing current and future corporate leaders. In its various chapters, the authors propose counter-populist approaches for effectively measuring political and socially responsible action and accountability. In this context, the authors offer tools to combat the causes of populism in both the political and social spheres, as well as in business.

Geisa Oliveira Daré

Resumo. As migrações internacionais estão na pauta da agenda política dos países, principalmente os desenvolvidos, uma vez que têm experimentado o crescimento da população imigrante e a diversificação dos países de origem em virtude dos efeitos da globalização. Sob o viés humanitário, é necessária a integração dos imigrantes nas respectivas sociedades de acolhimento. Todavia, os processos de integração nem sempre são satisfatórios. Um dos vieses da integração está relacionado aos direitos de cidadania. Partindo disso, o artigo busca analisar o tratamento jurídico e político dos direitos de cidadania dos imigrantes em Portugal, perpassando pelo direito à participação política, pelo direito à residência permanente e o acesso à nacionalidade. Observa-se um grande esforço por parte do governo português na instituição de órgãos para tratar da matéria afeta à imigração. No entanto, é preciso verificar em que medida a legislação e as ações portuguesas estão atendendo adequadamente o processo de integração dos imigrantes.

Alireza Behtoui

This study is about a relatively recent immigrant group — those with an Iranian background — and their pathways to advanced positions in the three fields of economics, politics and academia in Swedish society, despite the general processes of stigmatisation and subordination aimed at migrants from the global South. As the results of this study show, compared with other immigrant groups from the global South, individuals with an Iranian background, to a greater extent, were able to attain high-ranking positions in the fields of power investigated. These outcomes, as the results show, emerge from the resources that this group brought with them — their cultural and social capital — in interaction with external factors in their new country of residence (Sweden) over a specific time period.

Carine Pina

In China, the 1980 nationality law ended, a priori, once and for all, all ambiguities about the definition of acquisition, loss, and recovery of this legal tie with the Chinese continent. However, the relationships maintained and/or expected by Beijing with their old or new emigrants exceed this legal basis and are adapted as required by China’s needs and perceptions, as can be seen in the era opened by President Xi Jingping since 2013.

Santosh Pandey, Yunsoo Park, Ankita Ankita et al.

A hallmark of bacterial populations cultured in vitro is their homogeneity of growth, where the majority of cells display identical growth rate, cell size and content. Recent insights, however, have revealed that even cells growing in exponential growth phase can be heterogeneous with respect to variables typically used to measure cell growth. Bacterial heterogeneity has important implications for how bacteria respond to environmental stresses, such as antibiotics. The phenomenon of antimicrobial persistence, for example, has been linked to a small subpopulation of cells that have entered into a state of dormancy where antibiotics are no longer effective. While methods have been developed for identifying individual non-growing cells in bacterial cultures, there has been less attention paid to how these cells may influence growth in colonies on a solid surface. In response, we have developed a low-cost, open-source platform to perform automated image capture and image analysis of bacterial colony growth on multiple nutrient agar plates simultaneously. The descriptions of the hardware and software are included, along with details about the temperature-controlled growth chamber, high-resolution scanner, and graphical interface to extract and plot the colony lag time and growth kinetics. Experiments were conducted using a wild type strain of Escherichia coli K12 to demonstrate the feasibility and operation of our setup. By automated tracking of bacterial growth kinetics in colonies, the system holds the potential to reveal new insights into understanding the impact of microbial heterogeneity on antibiotic resistance and persistence.

Gautier, Ari

Abel Chikanda, Ines Raimundo

Informal cross-border trading is an essential part of Maputo’s informal economy. This paper presents the results of a 2014 SAMP survey of informal entrepreneurs involved in cross-border trade between Johannesburg and Maputo. A questionnaire was administered to a sample of 403 informal traders in 7 markets in Maputo. The study showed that most of the entrepreneurs began their business activities as vendors and only later moved into cross-border trading. The overwhelming majority used their personal savings to start their business and they face significant barriers in accessing business loans from formal banking channels. The study demonstrates the importance of cross-border traders to both the Mozambican and South African economy. In South Africa, the cross-border traders make a significant contribution by buying local goods and utilising the services provided by the country’s travel and hospitality industry. In Mozambique, they supply affordable products to the country’s growing informal sector and play an important role in generating employment.

TianZhang He, Rajkumar Buyya

Cloud Data Centers have become the backbone infrastructure to provide services. With the emerging edge computing paradigm, computation and networking capabilities have been pushed from clouds to the edge to provide computation, intelligence, networking management with low end-to-end latency. Service migration across different computing nodes in edge and cloud computing becomes essential to guarantee the quality of service in the dynamic environment. Many studies have been conducted on the dynamic resource management involving migrating Virtual Machines to achieve various objectives, such as load balancing, consolidation, performance, energy-saving, and disaster recovery. Some have investigated to improve and predict the performance of single live migration of VM and container. Recently, several studies service migration in the edge-centric computing paradigms. However, there is a lack of surveys to focus on the live migration management in edge and cloud computing environments. We examine the characteristics of each field and conduct a migration management-centric taxonomy and survey. We also identify the gap and research opportunities to guarantee the performance of resource management with live migrations.

Magnus Öhlander, Katarzyna Wolanik Boström, Helena Pettersson

This article addresses the relationship between highly skilled international mobility and knowledge by focussing on knowledge transfer work. Empirically, this study is based on interviews of professionals in the Swedish medical field who returned to Sweden after a period of work in other countries. The medical field harbours many transnationally valid competences and standardised lines of work, but even in this field, knowledge transfer is a process requiring effort, skills, negotiation, translation and adjustment to the specific organisational and cultural contexts. The studied professionals’ knowledge transfer work showed a spectrum, ranging from smooth, almost friction-free transfers to the ones where much translation and transformation was required, depending on the context and the professional’s status in the workplace. The professionals also developed and made use of knowledge transfer skills, such as the ability to observe, analyse and adjust to cultural differences between workplaces, healthcare systems or academic systems, as well as the ability to translate knowledge to make it relevant and viable in the specific context.

Maria Fernanda DJonsiles, Gustavo Ernesto Galizzi, Andres Ezequiel Dolinko et al.

Currently, the detection of endophytic fungi is determined mostly by invasive methods, including direct isolation of fungal organismsfrom plant tissue in growth media, molecular detection of endophyticfungi DNA from plant material by PCR, or evaluation under microscopy techniques.In this work we explore the potential of laser biospeckle activity (LBSA) to be usedfor the detection of endophytic colonization of leaves of a promising energy crop, Jatropha curcas L. We compared the laser biospeckle activityof endophyte infected and uninfected J. curcas leaves. The differences between blade and veins (including midrib) of the studied leaves was validated and growth parameters of the studied plants were also analyzed using the normalized weigthed generalized differencescoefficient (nWGD). The obtained results showeda relationship between the endophytic burden of leaves and the LBS, suggesting that LSBA is a useful tools to detect endophytic colonization in situ.Also, the increasedwater movements inside leaves promoted by endophytic colonizationcould be explainby the obtained data.

Caleb Robinson, Bistra Dilkina, Juan Moreno-Cruz

We propose a framework to examine future migration patterns of people under different sea level rise scenarios using models of human migration. Specifically, we couple a sea level rise model with a data-driven model of human migration, creating a generalized joint model of climate driven migration that can be used to simulate population distributions under potential future sea level rise scenarios. We show how this joint model relaxes assumptions in existing efforts to model climate driven human migration, and use it to simulate how migration, driven by sea level rise, differs from baseline migration patterns. Our results show that the effects of sea level rise are pervasive, expanding beyond coastal areas via increased migration, and disproportionately affecting some areas of the United States. The code for reproducing this study is available at https://github.com/calebrob6/migration-slr.

Colin P. McNally, Richard P. Nelson, Sijme-Jan Paardekooper

We examine the migration of low mass planets in laminar protoplanetary discs, threaded by large scale magnetic fields in the dead zone that drive radial gas flows. As shown in Paper I, a dynamical corotation torque arises due to the flow-induced asymmetric distortion of the corotation region and the evolving vortensity contrast between the librating horseshoe material and background disc flow. Using simulations of laminar torqued discs containing migrating planets, we demonstrate the existence of the four distinct migration regimes predicted in Paper I. In two regimes, the migration is approximately locked to the inward or outward radial gas flow, and in the other regimes the planet undergoes outward runaway migration that eventually settles to fast steady migration. In addition, we demonstrate torque and migration reversals induced by midplane magnetic stresses, with a bifurcation dependent on the disc surface density. We develop a model for fast migration, and show why the outward runaway saturates to a steady speed, and examine phenomenologically its termination due to changing local disc conditions. We also develop an analytical model for the corotation torque at late times that includes viscosity, for application to discs that sustain modest turbulence. Finally, we use the simulation results to develop torque prescriptions for inclusion in population synthesis models of planet formation.

Anna Gavanas

This article analyses the Swedish international retirement migrants (IRMs) in Spain and their consumption of domestic and eldercare services. In a transnational position and in the absence of stable structures and institutions (i.e., family, state and market provision), the IRMs are a part of liquid communities of care. It is argued that between themselves, and in relation to entrepreneurs and workers, the Swedish retirement migrants are part of a moral economy of care, reflecting the collective and individual consequences of the migration – as well as the labour market and welfare context in Spain. To IRMs, the moral economies mitigate the changing conditions of family and welfare in a transnational context. Solidarity and care among IRMs, as well as personalized relations with workers and intermediaries become even more important when relatives are physically absent and the Swedish welfare services (which are traditionally more extensive than the Spanish equivalent) are inaccessible. Therefore, the IRMs partake in a moral economy making gaps and inequalities more manageable, while creating coping strategies in the face of unaffordable market solutions.