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1.
The established consensus in sociology is to explain the transformations of the ethnic identities of migrants through processes by which the migrants combine features they share with co-ethnics with characteristics they adopt from other groups of residents. This conceptualization, however, works on the assumption that it is the differences and contradictions between the elements in the ethnic identities of the migrants, and the characteristics of other groups of residents, that motivate the transformations of migrant ethnic identities. Therefore, processes by which migrants adopt characteristics from other residents are understood to typically decrease the migrants’ differences from them. This analysis of the ethnic identity transformations of Muslims of Chinese, Indian, Pakistani, and mixed ethnic origin in Hong Kong refutes the validity of this interpretation. It shows that adopting characteristics from non-Muslim Chinese residents supported establishing multi-ethnic Islamic practices which, in turn, accentuated the differences of the Muslims from these majorities.  相似文献   

2.
Migration phenology is largely determined by how animals respond to seasonal changes in environmental conditions. Our perception of the relationship between migratory behavior and environmental cues can vary depending on the spatial scale at which these interactions are measured. Understanding the behavioral mechanisms behind population‐scale movements requires knowledge of how individuals respond to local cues. We show how time‐to‐event models can be used to predict what factors are associated with the timing of an individual's migratory behavior using data from GPS collared polar bears (Ursus maritimus) that move seasonally between sea ice and terrestrial habitats. We found the concentration of sea ice that bears experience at a local level, along with the duration of exposure to these conditions, was most associated with individual migration timing. Our results corroborate studies that assume thresholds of >50% sea ice concentration are necessary for suitable polar bear habitat; however, continued periods (e.g., days to weeks) of exposure to suboptimal ice concentrations during seasonal melting were required before the proportion of bears migrating to land increased substantially. Time‐to‐event models are advantageous for examining individual movement patterns because they account for the idea that animals make decisions based on an accumulation of knowledge from the landscapes they move through and not simply the environment they are exposed to at the time of a decision. Understanding the migration behavior of polar bears moving between terrestrial and marine habitat, at multiple spatiotemporal scales, will be a major aspect of quantifying observed and potential demographic responses to climate‐induced environmental changes.  相似文献   

3.
Abstract

Mediated representations of gender, ethnicity and migration play an increasingly important role in the way these categories are understood in the public sphere and the private realm. As media often intervene in processes of individual and institutional communication, they provide frameworks for the production and consumption of representations of these categories. Thus media – in their production, representations and consumption – need to be analysed, not only as reflections as pre-existing socio-political realities, but also as constitutive elements in the production of meanings of the self and the Other. This special issue includes a number of articles that examine the articulations of gendered ethnic identities and of gendered citizenship as these are shaped in media production, media representations and media consumption.  相似文献   

4.
This article examines how ethnic capital operates in ethnic affinity migration and external citizenship. Criticizing the “methodological nationalism”, inadequate theorization of the state, and “groupist” understanding of ethnicity that characterize existing scholarship on ethnic capital, I develop an alternative account drawing on Bourdieu. I highlight the importance of state power that consecrates ethnicity as a legitimate element in classifying non-citizens and determines the key criteria for coethnicity. The conversion of ethnicity into a migration-facilitating resource, however, is not monopolized by the state. I pay attention to how aspiring migrants, assisted by various intermediaries, challenge the state’s definition of ethnic group boundaries or deliberately cultivate specific ethnic markers, with varying implications for their ethnic self-understanding. Instead of treating ethnicity as what migrants are, I analyse what states, migrants, and intermediaries do with ethnicity – how they shape the valorization, conversion, and legitimization of ethnic capital in macro-political, meso-institutional, and micro-interactional contexts, with different agendas and asymmetrical power.  相似文献   

5.
6.
The tumultuous events of summer 2009 have brought Uighur protests and minority mobilization in the Xinjiang Uighur Autonomous Region (XUAR) to the forefront. But this focus overlooks similar protests organized by various groups of Han Chinese settlers over the years. This paper contributes to the body of literature on minority mobilization and ethnic relations in Xinjiang by illustrating how the political mobilization of a group that is simultaneously a national majority and a regional minority differs substantially from ‘traditional’ minority mobilization. Reviewing the main instances of Han Chinese political mobilization since the XUAR was created in 1955, I argue that two factors are particularly important in enabling their mobilization: the Han Chinese's subjective perception of discrimination and their close ethnic ties to the state. This paper concludes with a discussion on the presence of a cycle of protests between Han settlers and the Uighurs in Xinjiang.  相似文献   

7.
The hormone corticosterone (CORT) is an important component of a bird’s response to environmental stress, but it can also have negative effects. Therefore, birds on migration are hypothesized to have repressed stress responses (migration-modulation hypothesis). In contrast to earlier studies on long-distance migrants, we evaluate this hypothesis in a population containing both migratory and resident individuals. We use a population of partially migratory blue tits (Cyanistes caeruleus) in southern Sweden as a model species. Migrants had higher CORT levels at the time of capture than residents, indicating migratory preparations, adaptation to stressors, higher allostatic load or possibly low social status. Migrants and residents had the same stress response, thus contradicting the migration-modulation hypothesis. We suggest that migrants travelling short distances are more benefited than harmed by retaining the ability to respond to stress.  相似文献   

8.
Relying on in-depth interviews with higher education students and young graduates the study investigates the factors underpinning the participation patterns of second-generation Turks in the Dutch higher education system. The paper highlights how ethnic minority students accommodate the constraints faced by the Dutch educational system by rationalizing economics at professional colleges as a suitable alternative to studying medicine at university, an alternative that will meet both their aspirations for a more successful and secure life than their parents’ while maintaining the traditional family ties in line with the work-life balance offered by a ‘nine-to-five job’.  相似文献   

9.
Summary Insect tissues are supplied with oxygen by a system of long and highly branched cuticular tubes known as tracheae and tracheoles. During the growth of with imaginal discs in moths and butterflies, tracheole cells migrate distally from the base of the disc. Tracheoles radiate in a distal direction through the extracellular space sandwiched between the upper and lower epithelial surfaces of the wing.Migration of most cells is assumed to be governed by forces intrinsic to the cell. However, the movement of tracheoles is apparently a passive process whose motive force resides in adjacent epithelial cells. After epithelial cells are exposed to ecdysteroid hormones, these cells extend basal processes that are attracted to oxygen-rich tracheoles. By applying traction to the tracheoles with which they establish intimate contact, epithelial cells may control the pattern of their distribution within wing tissue.  相似文献   

10.
Gone Home challenges dominant representations of Appalachia as white, placing in the foreground the life histories of African Americans who hail from the coalfields of eastern Kentucky. The book reveals how mass migration shapes subjectivities, examining two generations of African Americans who migrated into and out of the coalfields between 1910 and 1970. The coalfields were a layover stop in an intergenerational migration from the rural South to urban centres in the North, Midwest, and West. This review reflects on the significance of the layover stop, both empirically and conceptually. One of the key contributions of Gone Home is to show how the layover stop was important not only in terms of time and place, but also in terms of collective identity. The review concludes by reflecting on interconnected themes of industrial ruination and intergenerational memory.  相似文献   

11.
华北地区昆虫秋季迁飞的雷达观测   总被引:14,自引:0,他引:14  
吴孔明  程登发  徐广  翟保平  郭予元 《生态学报》2001,21(11):1833-1838
1999年9-10月利用昆虫雷达对华北地区昆虫秋季回迁的观测表明,秋季迁飞主要发生于19:00-05:00时,飞行高度一般在300-2000m。迁飞方向与风向一致,多为从东北向西南方向迁飞。运行速度和飞行高度成正相关,迁飞个体的平均运行速度由392m高度的4.8m/s增加到2000m处的27.8m/s。空中灯光诱捕表明,甜菜夜蛾和棉铃虫为优势迁飞种类。  相似文献   

12.
《Current biology : CB》2021,31(24):5590-5596.e4
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13.
Based on an extensive questionnaire survey in three cities in Northwest China, this article identifies the factors influencing the sole, couple and family migration of Han and Hui. We find that Han migrants are more utility-oriented and tend to circulate among different places in order to maximize their utility. Hui migrants are more likely to seek opportunities to settle in destinations with their families. They rely on Hui communities and dedicate themselves to creating networks and accumulating social capital for their families. We suggest that the accumulation of bonding capital does not necessarily suggest the increase or decrease of bridging capital. Moreover, the ethnic community should be regarded neither in negative nor positive terms but rather as a coin with two sides, pro and con. The ethnic community is a vessel, which migrants can use for minimizing risks, improving livelihoods and fostering the settlement of families.  相似文献   

14.
Migration is fundamental in the life of many birds and entails significant energetic and time investments. Given the importance of arrival time in the breeding area and the relatively short period available to reproduce (particularly at high latitudes), it is expected that birds reduce spring migration duration to a greater extent than autumn migration, assuming that pressure to arrive into the wintering area might be relaxed. This has previously been shown for several avian groups, but recent evidence from four tracked Icelandic whimbrels Numenius phaeopus islandicus, a long distance migratory wader, suggests that this subspecies tends to migrate faster in autumn than in spring. Here, we 1) investigate differences in seasonal migration duration, migration speed and ground speed of whimbrels using 56 migrations from 19 individuals tracked with geolocators and 2) map the migration routes, wintering and stopover areas for this population. Tracking methods only provide temporal information on the migration period between departure and arrival. However, migration starts with the fuelling that takes place ahead of departure. Here we estimate the period of first fuelling using published fuel deposition rates and thus explore migration speed using tracking data. We found that migration duration was shorter in autumn than in spring. Migration speed was higher in autumn, with all individuals undertaking a direct flight to the wintering areas, while in spring most made a stopover. Wind patterns could drive whimbrels to stop in spring, but be more favourable during autumn migration and allow a direct flight. Additionally, the stopover might allow the appraisal of weather conditions closer to the breeding areas and/or improve body condition in order to arrive at the breeding sites with reserves.  相似文献   

15.
The arrival patterns of summer visitors to Britain and Ireland were monitored from 2002 to 2004 using large numbers of birdwatching lists collected by Migration Watch, an Internet-based survey. Records were only accepted from registered observers, and procedures for data validation were implemented. We show here how data on the frequency of occurrence from birdwatching lists can be analysed to estimate the timing and duration of the migration period. Aerial insectivores showed clear species-specific arrival patterns, with sand martins arriving first, followed in succession by swallows, house martins and finally swifts. Wheatears showed two peaks of arrivals, one for the British population and one for passage migrants from Greenland. The progression of arrivals from south to north and variation in arrival timing between years were also demonstrated. The method offers considerable potential for studying migration phenology at large spatial scales, and within Britain and Ireland it is now being applied throughout the year within the BTO/RSPB/BWI BirdTrack project. It could potentially be implemented at a continental scale, at which it would provide an important tool for measuring the growing impacts of global climate change on bird populations.  相似文献   

16.
Stochastic effects of climate and weather have a pervasive influence on the induction, performance and evolution of migration. In wing-dimorphic species, their influence on habitat quality, and on rates of development of the migrant itself, maintains variation in responses to environmental cues determining wing-form and migratory behaviour. Migrants flying above their flight boundary layer rely on winds to disperse them across landscapes in which their habitats are distributed. Patterns of distribution of habitat patches, and the influence of changing windspeeds and direction on the displacements of migrants, result in selection for variation in migratory potential at each migration. In subsequent migrations, this variation and stochastic effects of the winds on groundtracks of individual migrants ensure that their destinations ‘sample’ the landscapes they travel over. The extent and resolution of this sampling, by which migrants reach favourable habitats, depend on the components of migratory potential, their mode of inheritance, and genetic correlations between them, as well as on the characteristics of the winds on which they travel.  相似文献   

17.
18.
Previous laser flash photolysis investigations between 100 and 300 K have shown that the kinetics of CO rebinding with cytochrome P450(cam)(camphor) consist of up to four different processes revealing a complex internal dynamics after ligand dissociation. In the present work, molecular dynamics simulations were undertaken on the ternary complex P450(cam)(cam)(CO) to explore the CO migration pathways, monitor the internal cavities of the protein, and localize the CO docking sites. One trajectory of 1 nsec with the protein in a water box and 36 trajectories of 1 nsec in the vacuum were calculated. In each trajectory, the protein contained only one CO ligand on which no constraints were applied. The simulations were performed at 200, 300, and 320 K. The results indicate the presence of seven CO docking sites, mainly hydrophobic, located in the same moiety of the protein. Two of them coincide with xenon binding sites identified by crystallography. The protein matrix exhibits eight persistent internal cavities, four of which corresponding to the ligand docking sites. In addition, it was observed that water molecules entering the protein were mainly attracted into the polar pockets, far away from the CO docking sites. Finally, the identified CO migration pathways provide a consistent interpretation of the experimental rebinding kinetics.  相似文献   

19.
20.
Angiostatin, a circulating inhibitor of angiogenesis, was identified by its ability to maintain dormancy of established metastases in vivo. In vitro, angiostatin inhibits endothelial cell migration, proliferation, and tube formation, and induces apoptosis in a cell type-specific manner. We have used a construct encoding the kringle domains 1--4 of angiostatin to screen a placenta yeast two-hybrid cDNA library for angiostatin-binding peptides. Here we report the identification of angiomotin, a novel protein that mediates angiostatin inhibition of migration and tube formation of endothelial cells. In vivo, angiomotin is expressed in the endothelial cells of capillaries as well as larger vessels of the human placenta. Upon expression of angiomotin in HeLa cells, angiomotin bound and internalized fluorescein-labeled angiostatin. Transfected angiomotin as well as endogenous angiomotin protein were localized to the leading edge of migrating endothelial cells. Expression of angiomotin in endothelial cells resulted in increased cell migration, suggesting a stimulatory role of angiomotin in cell motility. However, treatment with angiostatin inhibited migration and tube formation in angiomotin-expressing cells but not in control cells. These findings indicate that angiostatin inhibits cell migration by interfering with angiomotin activity in endothelial cells.  相似文献   

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