Migrant Networks Research Articles

Human migration-based graph convolutional network for PM2.5 forecasting in post-COVID-19 pandemic age.

Due to the coronavirus disease 2019 pandemic, local authorities always implanted non-pharmaceutical interventions, such as maintaining social distance to reduce human migration. Besides, previous studies have proved that human migration highly influenced air pollution concentration in an area. Therefore, this study aims to explore whether human migration can work as a significant factor in the post-pandemic age to help PM2.5 concentration forecasting. In this work, we first analyze the variations of PM2.5 in 11 cities of Hubei from 2015 to 2020 and further compare PM2.5 trends with the migration trends of Hubei province in 2020. Experimental results indicate that the human migration indirectly affected the urban PM2.5 concentration. Then, we established a graph data structure based on the migration network describing the migration flow size between any two areas in the Hubei province and proposed a migration attentive graph convolutional network (MAGCN) for forecasting PM2.5. Combined with the migration data. The proposed model can attentively aggregate the information of neighbor nodes through migration weights. Experimental results indicate that the proposed MAGCN can forecast PM2.5 concentration accurately.

THE DYNAMICS OF MIGRANT SETTLEMENT IN ISTANBUL: THE CASE OF BEYOĞLU

Beyoğlu, İstanbul’un en hareketli nüfusa sahip merkez ilçelerinden biridir. İlçe giderek çeşitlenen ve artan oranlarda göçmen gruplarının mekâna tutunma, yerleşme, hareketlilik dinamikleri barınma ve çalışma olanaklarının yarattığı olumsallıklar paralelinde şekillenir. Kentsel haklara ve hizmetlere erişim düzeyleri ise göçmenlerin statülerine, göçmenlik ağlarına ve sınıfsal konumlarına göre değişkenlik göstermektedir. Amaç: Bu çalışma Beyoğlu ilçesi örneğinden yola çıkarak farklı göçmen gruplarının mekânda yerleşme/tutunma dinamikleri ve kentsel mekandaki ihtiyaç, sorun ve beklentilerine dair özgün nitel veriye dayalı bir analizle, göçmenlere yönelik üretilebilecek yerel sosyal politika ve uygulamalara katkı sağlamayı amaçlamaktadır. Yöntem: Nitel veri toplama teknikleriyle yapılan saha araştırması ilçedeki beş göçmen grup ile gerçekleştirilen altı odak grup toplantısı ile uzmanlar ve kamu kurumları temsilcilerinden oluşan 19 kişi ile yapılan mülakatlara dayanmaktadır. Bulguların analizi NVİVO nitel analiz programında araştırma ekibi tarafından yapılmıştır. Bulgular: Beyoğlu’ndaki en büyük göçmen grubunu geçici koruma statüsündeki Suriyeliler oluşturmakla birlikte, ilçede çok sayıda düzensiz ve kayıtsız göçmen mevcuttur. İlçedeki göçmen varlığının en önemli belirleyenleri ilçenin sosyo-mekânsal özellikleridir. On yıllardır metruklaşmakta olan konut stoku, düzensiz veya yoksul göçmenler için barınabilecekleri bir alan yaratmıştır. Ancak konutlar insani barınma koşullarını çoğu kez karşılamamaktadır. Kamu kurumlarının bazı mahallelerdeki sosyo-mekânsal koşullara yönelik kayıtsızlığı da ilçede kayıtsız ve düzensiz göçmenlerin yerleşimini kolaylaştırmaktadır. Beyoğlu’nda yoğunlaşan yeme-içme ve konaklama sektörleri ile küçük imalat sektörünün varlığını sürdürmesi, göçmenlere kayıt dışı çalışma olanakları sunmaktadır. Beyoğlu’ndaki göçmenlerin birçoğunun kayıtsız veya düzensiz olması, sağlık hizmetleri ve eğitim gibi temel haklara ve işgücü piyasalarına erişimlerini olumsuz etkilemektedir. Kayıtsız ve düzensiz göçmenlerin çocuklarının örgün eğitime erişimi yoktur. Kayıtsız Suriyelilerin çocukları arasında çocuk işçiliği de yaygındır. Göçmenlerin temel sağlık hizmetleri ve bulaşıcı hastalıklardan korunma ve tedavi hizmetlerine erişiminin çok yetersiz olması, halk sağlığı açısından da bir risk oluşturmaktadır. Kötü ve kalabalık konutlarda yaşayan kadın ve çocuk göçmenlerin mahalle içerisindeki birkaç park haricinde sosyalleşme mekanları neredeyse yoktur.Özgünlük: Çalışmada göçmenlerin mekâna yerleşimlerinde belirleyici olan sosyo-mekânsal örüntülerin tespiti ile farklı niteliklerdeki göçmen gruplarının mekâna yerleşme ve tutunma dinamikleri arasındaki ayrımlar ve benzerliklerin analizi göç alandaki çalışmalara özgün bir katkı sağlamaktadır.

The effect of self-organizing map architecture based on the value migration network centrality measures on stock return. Evidence from the US market.

Complex financial systems are the subject of current research interest. The notion of complex network is used for understanding the value migration process. Based on the stock data of 498 companies listed in the S&P500, the value migration network has been constructed using the MST-Pathfinder filtering network approach. The analysis covered 471 companies included in the largest component of VMN. Three methods: (i) complex networks; (ii) artificial neural networks and (iii) MARS regression, are developed to determine the effect of network centrality measures and rate of return on shares. A network-based data mining analysis has revealed that the topological position in the value migration network has a pronounced impact on the stock's returns.

FlywayNet: A hidden semi‐Markov model for inferring the structure of migratory bird networks from count data

Abstract Every year, millions of birds migrate between breeding and nonbreeding habitat, but the relative numbers of animals moving between sites are difficult to observe directly. Here we propose FlywayNet, a discrete network model based on observed count data, to determine the most likely migration links between regions using statistical modelling and efficient inference tools. Our approach advances on previous studies by accounting for noisy observations and flexible stopover durations by modelling using interacting hidden semi‐Markov Models. In FlywayNet, individual birds sojourn in stopover nodes for a period of time before moving to other nodes with an unknown probability that we aim to estimate. Exact estimation using existing approaches is not possible, so we designed customised versions of the Monte Carlo expectation‐maximisation and approximate Bayesian computation algorithms for our model. We compare the efficiency and quality of estimation of these approaches on synthetic data and an applied case study. Our algorithms performed well on benchmark problems, with low absolute error and strong correlation between estimated and known parameters. On a case study using citizen science count data of the Far Eastern Curlew (Numenius madagascariensis), an endangered shorebird from the East Asian–Australasian Flyway, the ABC and MCEM algorithms generated contrasting recommendations due to a difference in optimisation criteria and noise in the data. For ABC, we recovered key features of population‐level movements predicted by experts despite the challenges of noisy unstructured data. Understanding connectivity places local conservation efforts and threat mitigation in the global context, yet it has proven difficult to rigorously quantify connectivity at the population level. Our approach provides a flexible framework to infer the structure of migratory networks in birds and other organisms.

Highly cycle-stable and robust reversible protonic ceramic cells with air electrode supported structure enabled by single-step co-firing and infiltration

Due to the well-matched thermal expansion coefficient and small volume change, air electrode supported reversible protonic ceramic cells (AS-RePCCs) look promising in cyclic stability. In this work, AS-RePCCs are successfully fabricated at 1220 °C for the first time using the single-step co-firing technique. A tightly integrated interface and enriched proton migration network are created between the hydrogen electrode and electrolyte, which effectively promote the proton transfer and alleviate hydrogen partial pressure at the interface, enhancing the performance and stability of the cell. To further optimize the performance, nano La0.6Sr0.4CoO3 (LSC) particles are deposited into the air electrode matrix via infiltration. At 700 °C, the cell with 1.2 wt% LSC shows the maximum power density of 227 mW cm−2 and the current density of 543 mA cm−2 and 1113 mA cm−2 at 1.3 V and 1.5 V, respectively. More significantly, the performance remains stable during more than 60 rapid reversible cycles with a rate of one cycle every 2 h, followed by 30 deep thermal cycles (between 700 and 300 °C), demonstrating the excellent cyclic capability of single-step co-firing air electrode supported structure. This paper proposes a feasible scheme for developing AS-RePCCs with high performance, stability, and affordable manufacturing.

MEAT FROM HOME: MODES AND MEANINGS OF THE MOVEMENT OF MEAT PRODUCTS FROM DAGESTAN TO THE CITIES OF THE RUSSIAN ARCTIC

The translocal mode of labor migration between the Republic of Dagestan and the Arctic and subarctic cities of Western Siberia gives rise to specific practices of materiality associated with the transportation of things between sending and receiving societies. Food products in this series occupy the most prominent place both in terms of the scale of transfers and in terms of their importance in the daily life of migrants from Dagestan in northern cities.
 The article analyzes various options and mechanisms for the movement of meat and meat products through Dagestan migrant networks. Attention will be paid to the movement of meat as a multi-stage process - from its preparation in Dagestan to the organization of a storage system in a migrant's family. In this case, both commercial transfers and family and compatriot parcels will be of interest, since in both cases similar schemes can be used and the same networks are involved. Meat, intended primarily for migrants, becomes a migrant itself in the process of shipment, its appearance in the place of migration is endowed with meanings and characteristics associated with migration between these regions as a whole.
 Through the role and scale of the use of Dagestan meat in the daily practices of migrants' nutrition, the article demonstrates one of the aspects of constructing the translocal world of Dagestanis working in Arctic cities. In particular, of interest are the reciprocity regime both within the migrant community and between migrants and non-migrants in Dagestan, as well as the construction of symbolic representations of an abandoned house and a house built in migration, reflection on the degree of complementarity of the material worlds of Dagestan and the north, their fundamental differences and benefits.

A Review of Transnational Migrant Entrepreneurship: Perspectives on Unequal Spatialities.

The spatialities of migrant entrepreneurship have changed dynamically in recent decades. Movements and exchanges transcend national borders more than ever, and transnational migrant entrepreneurship has become a burgeoning field of research. Yet, knowledge is dispersed across disciplines, and an understanding of contemporary spatialities is limited. We review 155 articles published in English, French, German, and Spanish since 2009, thereby providing an overview of existing knowledge on transnational migrant entrepreneurship and suggesting avenues for future research. We identify five current topical areas of research: (1) the business advantages of transnational migrant entrepreneurship, (2) the determinants of becoming a transnational migrant entrepreneur, (3) the transnational networks of migrants, (4) the economic impacts of transnational migrant entrepreneurship on home and host countries, and (5) whether local environments enable or deter entrepreneurial success. Building on our synthesis of the most recent literature, we propose three crucial dimensions which have been under-researched in past and current work, and which address the diversity of geographical locations, spatial connections, and spatial mobilities involved in transnational migrant entrepreneurship. Moreover, we put forward a set of questions for future research which will advance a comprehension of unequal opportunities among transnational migrant entrepreneurs.

Network Analysis of the Gender Gap in International Remittances by Migrants

Financial inclusion is considered a key enabler of international development goals. Despite the expansion of financial access overall, the gender inequalities in basic access have remained consistent. This research investigates the predictive power of global remittance and migration flows on the gender gap in financial inclusion. First, singular value decomposition is applied to the World Bank’s 2017 Global Findex data to identify the financial inclusion variables that most contribute to the gender gap in financial inclusion. We find that indicators pertaining to account ownership, emergency funding, and receiving payments are especially significant. Based on the identified variables, a novel Financial Inclusion Gender Gap Score is calculated for 143 economies. The score is then incorporated into a complex network analysis of global remittance and migration networks. We analyze how network features such as node attributes, community membership, and bow-tie structure can be used to make inferences about the magnitude of a financial inclusion gender gap. Our findings suggest that weaker linkages in the network, characterized by lower node strength and peripheral positions in the bow-tie structure, are determinants of a notable financial inclusion gender gap. We also highlight communities in the remittance and migration networks with a more substantial gender imbalance, and discuss the the social- and cultural-leaning factors driving community formation in the migration network that seem to predicate a greater gap.

Who Matters Most? Migrant Networks, Tie Strength, and First Rural–Urban Migration to Dakar

Social networks' influence on migration has long been explored largely through the lenses of cumulative causation and social capital theory. This article aims to reconceptualize elements of these theories for the case of rural-urban migration and test their utility in explaining first-migration timing. We use a uniquely extensive social network survey linked to prospectively collected migration data in rural Senegal. We decompose migrant networks into return migrants, current migrants, and nonmigrant residents of the destination to capture heterogeneity in migration-relevant social capital. As expected, the number of nonmigrant alters living in the capital, Dakar, has an outsized association with the migration hazard, the number of current migrants from the village living in Dakar has a smaller association, and the number of return migrants has little association. Drawing on social capital theory, we test the influence of (1) subjectively assessed tie strength between the ego and their network alters and (2) structurally weak ties measured through second-order ("friend of a friend") connections. Weak and strong subjective ties to current migrants and nonmigrant Dakar residents are positively associated with the first-migration hazard. Structurally weak ties to current migrants are too, but only for individuals with no direct ties to current migrants.

Voice of the Silenced Peoples in the Global Cold War: The Assembly of Captive European Nations, 1954–1972

Voice of the Silenced Peoples in the Global Cold War: The Assembly of Captive European Nations, 1954–1972

Developing a high-performance electromagnetic microwave absorber using BaTiO3/CoS2/CNTs triphase hybrid

Toward the development of a novel electromagnetic microwave absorber, a CNTs-modified BaTiO3/CoS2 ternary nanostructure was synthesized by the hydrothermal method. BaTiO3/CoS2 nanocomposite was connected by CNTs, forming conductive networks for electron migration and hopping. An array of techniques were used to characterize the products, including XRD, BET, FTIR, Raman, XPS, FESEM, HR-TEM, and VNA. For the BaTiO3/CoS2/CNT nanocomposite, a Minimum reflection loss (RLmin) of −72.2 dB (99.999 95% wave absorption) was recorded for thicknesses of 4 mm at 4.44 GHz. Furthermore, the effective absorption bandwidth (EAB) of 6.9 GHz was obtained with a coating thickness of 1.5 mm. Moreover, the RL values for the pure BaTiO3 phase and BaTiO3/CoS2 binary nanocomposite, respectively, reach −20.3 dB and −42.5 dB. The specific RL values (SRL1t and SRL1), impedance matching (|Δ|) as well as EAB values of the prepared nanocomposite were much better than those of the previous BaTiO3-based absorbers. To explain the microwave absorbing properties, the conductive loss and magnetic loss mechanisms were thoroughly investigated.

'Daniel Davy, Gold Rush Societies and Migrant Networks in the Tasman World'

Melanie Burkett Stanford University melb2001@gmail.com https://orcid.org/0000-0002-8080-8485 Journal of Australian, Canadian, and Aotearoa New Zealand Studies 2 (September 2022): 92-93, https://doi.org/10.52230/ZBQK4253 Book Review

Social Network Analysis of Indonesia Migrant Workers in Hong Kong: Study Social Integration Between Health Care and “KOTKIHO”

In the research, the relationship between the social networks of migrant domestic workers from Indonesia in Hong Kong and the accessibility of medical care and legal protection is investigated. To help others and support the struggle of BMI organizations and groups in Hong Kong, the Coalition of Indonesian Labor Organizations in Hong Kong (KOTKIHO) was founded out of concern and solidarity.. Similarly, participant observations from formal and informal activities were used in this research, which also drew on field notes. In order to control risk and gain access to resources for their health and well-being, KOTKIHO strategically use their strong and weak ties, deciding within their social network who and what to discuss with reference to medical issues. For characterizing and assessing the continuous dynamic social integration process, researchers suggest using social network analysis. Their employers, who can also provide them with access to institutional and social resources, are carefully negotiated with regarding their rights and opportunities. Participate in online discussions and debates regarding the health policies of their native and host nations. To better comprehend the complexity and intricacy of social integration, social network analysis must be done using a mixed-methods approach due to its limitations as a relatively new tool in the field of social integration research. It also demonstrates the establishment, activation, and mobilization of migrant social networks around discourses on state-designed immigration-related health policy

Transformation of international migrants in head wind: Evidence from Tajikistan in the 2010s

AbstractTajikistan has relied on remittances by international migrants that have exceeded a quarter of annual GDP to date, despite a series of exogenous adverse events in the mid‐2010s. We use a nationally representative panel dataset collected in 2013 and 2018 to explore the socio‐economic characteristics of households with international migrants and migrants themselves. We provide several new findings. First, the prevalence of households with international migrants is 40%, with a substantial transition in migrant status during the research period. Second, households with international migrants are not poor, have Russian‐speaking members, and are supported by an intense migration network. Third, younger, single, and more educated males comprise most of Tajikistan's international migrants. Fourth, households without Russian‐speaking members or migration networks in 2013 had begun to send international migrants by 2018, while households in the richest group had exited from migration, suggesting s transition of the socio‐economic composition of migrant‐sending households during the mid‐2010s.

Study on properties of copolymers based on different types of benzoxazines and branched epoxy resins

Previous studies on linear epoxy (bisphenol A epoxy) resin/benzoxazine composites showed that with the addition of epoxy (EP) resin, the resulting copolymers exhibited an increased glass transition temperature ( Tg) ( Tg reached a maximum value at a specific content), improved flexural strength, lower heat resistance, and reduced tensile strength. Herein, branched EP resin (AG-80)/benzoxazine copolymers featuring novolac (N-box) and siloxane (Si-box) chains were prepared without any external curing agent. In both systems, the EP resin endowed the copolymers with an increased crosslinking density; however, Tg continued to increase with increasing EP content. In addition, the heat resistance of the copolymers gradually enhanced. Different types of benzoxazines have various effects on the properties of copolymers. In terms of mechanical properties, AG-80/N-box copolymers exhibited brittle fracture characteristics; with increasing EP content, the flexural strength of the copolymer decreased while the tensile strength increased. AG-80/Si-box copolymers exhibited ductile fracture characteristics, with gradual increases in flexural and tensile strengths. Furthermore, with increasing EP content, the molecular chain migration ability and network homogeneity of the AG-80/N-box copolymers decreased gradually. Alternatively, in the case of the AG-80/Si-box copolymers, the molecular chain migration ability remained unchanged and network homogeneity improved. Hence, the developed copolymers can be used as resin matrices for the fabrication of advanced composites.

Genomic analysis of a reef-building coral, Acropora digitifera, reveals complex population structure and a migration network in the Nansei Islands, Japan.

Understanding the structure and connectivity of coral populations is fundamental for developing marine conservation policies, especially in patchy environments such as archipelagos. The Nansei Islands, extending more than 1000 km in southwestern Japan, are characterized by high levels of biodiversity and endemism, supported by coral reefs, which make this region ideal for assessing genetic attributes of coral populations. In this study, we conducted population genomic analyses based on genome-wide, single-nucleotide polymorphisms (SNPs) of Acropora digitifera, a common species in the Nansei Islands. By merging newly obtained genome resequencing data with previously published data, we identified more than 4 million genome-wide SNPs in 303 colonies collected at 22 locations, with sequencing coverage ranging from 3.91× to 27.41×. While population structure analyses revealed genetic similarities between the southernmost and northernmost locations, separated by >1000 km, several subpopulations in intermediate locations suggested limited genetic admixture, indicating conflicting migration tendencies in the Nansei Islands. Although migration networks revealed a general tendency of northward migration along the Kuroshio Current, a substantial amount of southward migration was also detected, indicating important contributions of minor ocean currents to coral larval dispersal. Moreover, heterogeneity in the transition of effective population sizes among locations suggests different histories for individual subpopulations. The unexpected complexity of both past and present population dynamics in the Nansei Islands implies that heterogeneity of ocean currents and local environments, past and present, have influenced the population structure of this species, and similar unexpected population complexities may be expected for other marine species with similar reproductive modes.

MicroRNA-375 repression of Kruppel-like factor 5 improves angiogenesis in diabetic critical limb ischemia.

Peripheral artery disease (PAD) is an occlusive disease of limb arteries. Critical limb ischemia (CLI) is an advanced form of PAD that is prognostically worse in subjects with diabetes and can result in limb loss, gangrene, and death, although the underlying signaling mechanisms that contribute to its development remain poorly understood. By comparing plasma samples from diabetic humans with PAD and mouse models of PAD, we identified miR-375 to be significantly downregulated in humans and mice during progression to CLI. Overexpression of miR-375 was pro-angiogenic in endothelial cells in vitro and induced endothelial migration, proliferation, sprouting, and vascular network formation, whereas miR-375 inhibition conferred anti-angiogenic effects. Intramuscular delivery of miR-375 improved blood flow recovery to diabetic mouse hindlimbs following femoral artery ligation (FAL) and improved neovessel growth and arteriogenesis in muscle tissues. Using RNA-sequencing and prediction algorithms, Kruppel-like factor 5 (KLF5) was identified as a direct target of miR-375 and siRNA knockdown of KLF5 phenocopied the effects of miR-375 overexpression in vitro and in vivo through regulatory changes in NF-kB signaling. Together, a miR-375-KLF5-NF-kB signaling axis figures prominently as a potential therapeutic pathway in the development CLI in diabetes.

Itinerant merchants: between networks of migrants and survival strategy (16th–20th)

ABSTRACT In dictionaries as well as in literature, the pedlar is an ambiguous figure. Urban sources testify to the desire of the urban authorities and sedentary merchants to exclude them. A few bankruptcy files do, however, make it possible to document failures as well as to provide information on the tours and the credit necessary to exercise the trade. However, to overcome the purely urban viewpoint, one must leave the town behind and concentrate instead upon the home villages and its notarial archives in order to link individual departures to the social framework to which they belonged and to understand the organisation of these networks of migrants. However, the municipal archives on poverty, on markets, as well as the archives of the police, justice and guilds allow us to enter into certain economic practices of the most destitute. In the first part, the essay describes the organisation of migrant networks and their evolution between the sixteenth and twentieth centuries. In the second part, it analyses urban peddling, which is the economic resource of the poorest people, particularly women, and the battles waged against them by the elites and established merchants in order to keep them off the streets.

Rebel Imaginaries: Labor, Culture, and Politics in Depression-Era California

Rebel Imaginaries: Labor, Culture, and Politics in Depression-Era California

How Does Migration Affect HIV Sexual Risk Behaviors Among Involuntary Bachelors? The Mediating Roles of Neighborhoods and Social Networks.

The sex ratio imbalance in China since the 1980s has resulted in a large number of involuntary bachelors in rural China. Previous studies have found an association between migration and HIV sexual risk behaviors among involuntary bachelors, but how migration affects these bachelors' HIV sexual risk behaviors remain poorly understood. Using data from a cross-sectional survey in 2017 (a sample of 740 male respondents who had rural household registration, had never been married, and were aged 28-49 years), we investigated the relationship between migration and HIV sexual risk behaviors. Logistic regressions show that migration, neighborhood characteristics, and social networks were significantly associated with commercial sex and multiple sex partners, whereas only neighborhood characteristics and social networks were positively correlated with sexual partnership concurrency. Neighborhood characteristics and social networks mediated the relationships of migration with commercial sex and migration with multiple sex partners. Social networks mediated the association between neighborhood characteristics and concurrency. Multiple-step mediation analysis showed that the indirect effect of migration on commercial sex and multiple sexual partners through neighborhood characteristics and social networks was significant. Our findings suggest that further interventions should address neighborhood characteristics and social networks together.