Macrophage migration inhibitory factor (MIF) is a multifunctional cytokine that promotes neurogenesis and neuroprotection. MIF is predominantly expressed in astrocytes in the brain. The serum MIF ...level and microsatellites/single nucleotide polymorphisms (SNPs) in the MIF gene promoter region are known to be associated with schizophrenia (SCZ). Interestingly, previous studies reported that hypoxia, an environmental risk factor for SCZ, induced MIF expression through binding of the hypoxia inducible factor (HIF)-1 to the hypoxia response element (HRE) in the MIF promoter.
We investigated the involvement of MIF in SCZ while focusing on the HIF pathway. First, we conducted an association study of the SNP rs17004038 (C>A) in the HRE of the MIF promoter between 1758 patients with SCZ and 1507 controls. Next, we investigated the effect of hypoxia on MIF expression in primary cultured astrocytes derived from neonatal mice forebrain.
SNP rs17004038 was significantly associated with SCZ (p = 0.0424, odds ratio = 1.445), indicating that this SNP in the HRE of the MIF promoter was a genetic risk factor for SCZ. Hypoxia induced MIF mRNA expression and MIF protein production and increased HIF-1 binding to the MIF promoter, while the activity of the MIF promoter was suppressed by mutations in the HRE and by deletion of the HRE in astrocytes.
These results suggest that SNP rs17004038 in the HRE of the MIF promoter was significantly associated with SCZ and may be involved in the pathophysiology of SCZ via suppression of hypoxia and HIF pathway-induced MIF expression.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The argument that environmental change is an important driving force of migration has experienced a strong revival in the climate change context. While various studies predict large environmental ...migration flows due to climate change and other environmental events, the ex post empirical evidence for this phenomenon is inconclusive. We contribute to the extant literature by focusing on the micro-level. We examine whether and how individual perceptions of different types of environmental stressors induce internal migration. The analysis relies on original survey data from Vietnam including both migrants and non-migrants. The results suggest that individual perceptions of long-term environmental events, such as droughts, significantly reduce migration while perceptions of sudden-onset environmental events, such as floods, significantly increase the likelihood of migration controlling for other determinants of migration. These findings also imply that improving the targeting of aid to environmental disaster-affected areas and the financial and technical support for adaptation to environmental change could be the most productive policy-options. Policymakers, thus, need to implement a wide range of developmental policies in combination with environmental ones in order to improve society’s ability to effectively cope with environmental change and minimize its effect on migration.
This paper examines the impact of COVID-19 pandemic on migration. The rapid spread of the pandemic caught countries across the world off guard, resulting in widespread lockdowns that clamped down on ...mobility, commercial activities and social interactions. In India, the pandemic precipitated a severe ‘crisis of mobility’, with migrant labourers in many major cities seeking to return to their hometowns. Their desperate attempts to return home by any means available rendered the lockdown ineffective in several areas, prompting clashes with authorities, last-minute policy relief and, eventually, the arrangement of transport measures. This paper aims to shed light on the vulnerability of India’s internal migrants in terms of their mobility, gender and mental health. In addition, it critically analyses the limitations of public policy in addressing migrants and suggests recommendations for the way ahead.
By analyzing the migration behavior and transnational residential strategies of first-generation, aging migrants from a particular Moroccan sending region, this study contributes to a conceptual ...critique of migration theories that identify the household as the most relevant decisionmaking unit. It highlights the role of intra-household power inequalities and conflicts in migration decisionmaking as well as the effects of migration decisions for intra-household power relations. Many labor migrants who left Morocco to work in Europe in the 1960s and 1970s did not realize their wish to return but instead ended up reunifying their families at the destination. An increasing proportion adopts a pendulum migration strategy to reconcile their own wish to retain strong ties with Morocco with the reluctance of children and spouses to return. Migrants who unilaterally decided not to reunify their families usually return after their active working life. However, this unilateral decision also blocks legal entry into Europe for their children, which has generated considerable intergenerational tensions.
•Exploiting quasi-random exposure to returnees, we show that individuals alter their migration aspirations when return migrants live in their vicinity.•Individuals who are exposed to return migrants ...from Europe have lower migration aspirations, while returnees from other African countries do not affect migration aspirations.•These effects can be explained with negative experiences on the dangerous route to Europe and returnees from Europe being stigmatized as “failures” - stories that circulate through weak ties in a location.
Information and networks have long been hypothesized to be crucial elements of the formation of emigration intentions. Returnees are a prime source of information about life as a migrant. In this study, we contribute to an emerging literature on the influence of returnees on the formation of migration decisions using representative geolocated data from 5,000 respondents and more than 47,000 family members and relatives from Senegal and The Gambia, two countries with high emigration rates in the past. We demonstrate that the presence of return migrants in a respondent’s vicinity is exogenously conditional on the current number of emigrants. This allows us to circumvent the endogeneity of personal networks and to estimate the effect of returnees on individual emigration intentions. Migration intentions are substantially lower when emigrants who returned from Europe are present in the area. This does not apply to returnees from another African country. Further analyses reveal that migrants who returned from another African country improve the economic situation of families, while non-family returnees from Europe have no lasting economic impact but instead salter people’s negative perceptions of migration. We infer that exposure to returnees depresses emigration plans because potential migrants become more aware of the risks of the migration journey and the stigma attached to returning unsuccessfully.
The effect of immersion freezing on water distribution and calcium ion migration in pears was studied. The samples were frozen at -20 °C and -40 °C. Results showed that the -40 °C combined immersion ...freezing (-40IF-T) was better in inhibiting sample browning and sensory quality, compared with other groups. Water activity and freezable water content were closer to that of the unfrozen sample. Compared with -20IF, the freezing time of -40IF-T was reduced by 74.90 %. Both the drip loss and calcium ion content showed that -40IF-T was better than other groups. Low-field nuclear magnetic resonance results showed that -40IF-T reduced water migration during freezing, indicating a more uniform distribution of water in -40IF-T tissues. The results of relative conductivity showed that -40IF-T could effectively reduce the damage of cell membrane caused by freezing. In conclusion, low temperature and cryoprotective fluid can be used as effective methods to maintain sample quality.
Electronic tracking tags have revolutionized our understanding of broad-scale movements and habitat use of highly mobile marine animals, but a large gap in our knowledge still remains for a wide ...range of small species. Here, we report the extraordinary transequatorial postbreeding migrations of a small seabird, the sooty shearwater, obtained with miniature archival tags that log data for estimating position, dive depth, and ambient temperature. Tracks (262 ± 23 days) reveal that shearwaters fly across the entire Pacific Ocean in a figure-eight pattern while traveling 64,037 ± 9,779 km roundtrip, the longest animal migration ever recorded electronically. Each shearwater made a prolonged stopover in one of three discrete regions off Japan, Alaska, or California before returning to New Zealand through a relatively narrow corridor in the central Pacific Ocean. Transit rates as high as 910 ± 186 km·day⁻¹ were recorded, and shearwaters accessed prey resources in both the Northern and Southern Hemisphere's most productive waters from the surface to 68.2 m depth. Our results indicate that sooty shearwaters integrate oceanic resources throughout the Pacific Basin on a yearly scale. Sooty shearwater populations today are declining, and because they operate on a global scale, they may serve as an important indicator of climate change and ocean health.
Aim
The configuration of the earth's landmasses influences global weather systems and spatiotemporal resource availability, thereby shaping biogeographical patterns and migratory routes of animals. ...Here, we aim to identify potential migratory barriers and corridors, as well as general migration strategies within the understudied Indo‐European flyway.
Location
Europe, Central Asia.
Major taxon studied
Common rosefinches.
Methods
We used a combination of theoretical optimization modelling and empirical tracking of Common Rosefinches (Carpodacus erythrinus) breeding across a large latitudinal gradient in Europe. First, we identified optimal migration routes driven by wind and resource availability along the Indo‐European flyway. Second, we tracked rosefinches from five breeding populations using light‐level geolocators. Finally, we compared to what extent empirical tracks overlapped with the modelled optimal routes.
Results
In autumn, theoretical wind driven migration routes formed a broad‐front corridor connecting Europe and the Indian Subcontinent while the theoretical resource driven routes formed a distinct north‐south divide. The latter pattern also reflected the rosefinch tracks with all but the most southerly breeding birds making a northern detour towards non‐breeding sites in Pakistan and India. In spring, the resource availability model predicted a similar migratory divide, however, the southern route seemed relatively more favourable and closely matched with the optimal wind driven migration routes. Spring tracking data showed larger overlap with the modelled wind driven migration routes compared to the resource driven routes.
Main conclusions
Optimal wind and resource driven migration routes along the Indo‐European flyway are seasonally specific and to a large extend do not overlap with one another. Under these conditions, migratory birds adopt seasonally distinct migration strategies following energy minimization strategy in autumn, driven by resource availability, and time minimizing strategy in spring, driven by wind conditions. Our optimal migration models can be applied worldwide and used to validate against empirical data to explain large‐scale biogeographic pattern of migratory animals.
In light of increasing environmental stress and its likely implications for migration patterns, we conduct a cross-country individual-level analysis of the impact of self-reported exposure to ...environmental stress on people's migration intentions and their destination choice. We simultaneously model intentions to migrate domestically and internationally for 90 countries worldwide in 2010. We find that self-reported exposure to environmental stress increases the probability to intend to migrate both domestically and internationally in the coming year. In absolute terms, the largest impact is obtained for domestic migration, but controlling for the fact that this is the most common form of migration anyway, environmental stress particularly raises intraregional migration intentions. Overall, the effects on migration intentions to the different destinations are strongest in low- and middle-income countries in Africa and Latin America and the Caribbean, while in high-income countries, and in Europe particularly, environmental stress appears to spur only domestic migration intentions.
There are only a few studies that analyze the complex relationship between Migration and development in Africa. The book presents the main trends in African migration since the last two decades. It ...analyzes the major migration trends, the various migration hubs across the continent and the underlying factors explaining the changing nature of migration across the continent. A few of the chapters in the book examine the phemen of migration from a national perspective by focusing on migration trends in countries such as Ghana, Cameroon, Kenya, and Nigeria. Two chapters examine the migration links between Africa and Europe with one of them focusing on the political links between Ghana and the Netherlands while the other focuses on ecomic exchanges between the Cameroonian diaspora in Germany and selected groups and organizations in Cameroon. The uniqueness of this book lies in the varied disciplinary viewpoints used by the authors in explaining the phemen of migration and development in Africa. The authors are specialists in the fields of sociology, anthropology, geography, history, philosophy and migration studies. Examining migration from so many different perspectives enriches the analysis and brings in new insights that would otherwise have been missing with the use of a single disciplinary perspective. The book recommends the need for policy coordination by national governments of both origin and destination countries to manage the size and composition of migrants. Most migrant-receiving countries prefer to receive professionals and persons with the required skills and training while keeping out the bulk of untrained and lowly-skilled persons. The result of this is that most migrants leave their countries and enter their destination countries illegally, swelling the numbers of undocumented immigrants
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