Mapping Dominican transnationalism: narrow and broad transnational practices

This article maps the structure for understanding the Dominican transnational field. By transnational field we refer to a web of linkages that affects the lives of Dominicans in their places of residence in every social field. We find that social boundaries of the nation do not coincide with political ones and the degree of participation in transnational exchanges varies. We suggest that the structure of the transnational social field is better understood by establishing and defining broad and narrow transnational social practices.     

Entrapped transnationalism: West Bank and Israeli Palestinians between closeness and distance

Studies of transnationalism typically frame it in opposition to the entrapping effects of borders. Yet, for many people, transnationalism is negotiated in contexts marked by forced separation and differential mobility. Drawing on long-term fieldwork among West Bank and Israeli Palestinians, this article explores transnational ties and orientations in relation, not in opposition, to the entrapping effects of borders. Specifically, I examine the two-way traffic in emotions and perceptions that marks family, social and symbolic relationships between West Bank and Israeli Palestinians. I show how entrapping and transnational processes combine to generate a tense interplay between closeness and distance, solidarity and estrangement. The paper calls attention to complex transnational formations among people prone to entrapment such as detained and deported migrants, refugees and minorities divided by rigid borders, and it suggests that a focus on emotions and perceptions is critical if we are to understand such formations.     

Transnational migration: a view from Colombia

This article presents the preliminary results of an ongoing research project on US-bound Colombian migration from the cities of Cali and Pereira. The project identified a dense web of economic, political, and socio-cultural transnational relations connecting migrants and their places of origin. These relations are heterogeneous and differentiated; what some scholars refer to as transnational communities are, in fact, fragmented by class, regionalism, ethnic cleavages and dominant stereotypes of Colombians as drug traffickers. We observed a complex transnational field of action, but not the formation of a transnational community.     

Transnational dynamics in researching migrants: self-reflexivity and boundary-drawing in fieldwork

Abstract

This article links migrant transnationalism with methodological debates, in particular the researcher's positionalities and self-reflexivity, which have so far barely been addressed in transnational studies in any systematic manner. Drawing upon my fieldwork experience in a German city, ‘Schönberg’, it examines the process of boundary-drawing and re-drawing between the research participants and the researcher. While there is undeniably a clear power hierarchy between the two parties that originates in national belonging, other positionalities such as gender, ethnicity, class and stage in the life cycle may, at their intersection, work to reverse such an asymmetrical relationship. Boundaries between ‘us’ and ‘them’ are not static and are, rather, created in a situational manner. Thus, attending to multiple positionalities in their intersection in research processes may help the researcher to re-evaluate the naturalized primacy given to national belonging.     

Transnational cyberpublics: new political spaces for labour migrants in Asia

This article offers a cultural interpretation of transnational solidarities that Asian political activists are generating through electronic telecommunications networks. Its focus is on the experiences of the Migrant Forum in Asia [MFA], a network of non-government organizations that question issues of human rights, citizenship and working conditions of labour migrants in the Asian region. MFA's networking activities are being transformed as email enables daily conversations across multiple national borders, and new 'imagined' communities of political action have emerged. English has been chosen as the language of solidarity, and photographs have become important in communicating activities and ideas. These media are innovative modes of transnational communication and shape political spaces that exist in symbiotic relation to the 'real'. Attention to these practices, spaces and the symbolic meanings activists attach to these communities helps to illuminate a cultural politics of transnational activism in this region.     

温度和CO2浓度升高下转Bt水稻种植对土壤活性碳氮和线虫群落的短期影响

全球气候变化下转Bt水稻种植对土壤生态系统的影响仍是未知领域。利用野外开顶式气室(OTC)模拟气候变化,探讨了温度和CO2浓度([CO2])升高后种植转Bt(华恢1号)水稻对土壤活性碳氮和线虫群落的影响。结果表明:(1)温度和[CO2]升高条件下种植转Bt水稻显著影响土壤可溶性碳(DOC)、可溶性氮(DON)和硝态氮(NO-3-N)含量,同时DOC和DON受到升温和[CO2]升高与转Bt水稻的交互影响;在正常温度和[CO2]下,转Bt水稻显著降低了土壤微生物量碳氮含量(MBC、MBN),但在温度和[CO2]升高后转Bt水稻种植使土壤MBC和MBN含量显著高于亲本水稻。(2)在温度和[CO2]升高条件下,转Bt水稻土壤线虫总数呈高于亲本水稻的趋势,植食性线虫的比例随[CO2]和温度升高呈增大的趋势。此外,升温和转Bt水稻种植提高了土壤线虫群落的能流通道指数,而[CO2]升高和转Bt水稻种植则提高了土壤线虫群落的富集指数。总之,在模拟全球气候变化下,种植转Bt水稻在短期内对土壤活性碳氮和线虫群落均产生影响,但短期研究并未发现转Bt水稻种植对土壤生态系统的不利影响。     

Mistrust,fragmented solidarity,and transnational migration: Colombians in New York City and Los Angeles

This article compares the transnational economic, political, and sociocultural relations of Colombian migrants residing in two different locations in the United States. The vast majority of these migrants are middle class and originally from large urban areas, which differs from the typical rural-origin migrants previously studied by transnational scholars. The analysis is based on theoretical developments from transnational studies and insights advanced by economic sociology. Our findings suggest that transnational relations and activities do not follow a linear path and are not necessarily and inevitably a progressive process. The reach, scope and effects of transnational activities are contingent on the interaction of multiple contextual (state of origin-migrants relations; state of origin relations with country of destination; context of reception of immigrants abroad) and group factors (size, class composition, mode of settlement).     

The limits to 'transnationalism': Bosnian and Eritrean refugees in Europe as emerging transnational communities

This article explores limitations on the concept of transnationalism, through examination of two empirical case studies of communities characterized by emerging transnational practices. Mirroring recent shifts of attention in studies of transnational migration away from US-based examples of established migrant workers, the article focuses on Bosnian refugees in the UK and The Netherlands, and Eritrean refugees in the UK and Germany. It stresses the importance of historical context, and the interconnection of social, political and institutional factors in producing highly uneven patterns of transnational activities both within and between these two groups.     

Resource limitation,habitat segregation,and species interactions of british tree-hole mosquitoes in nature

Summary The insect fauna of water-filled tree holes in southern Britain consists primarily of the mosquitoes Aedes geniculatus, Anopheles plumbeus, Culex torrentium, and a benthic detritivorous fauna that includes primarily the scirtid beetle Prionocyphon serricornis and the chironomid midge Metriocnemus martinii. Culex torrentium has been documented only relatively recently in tree holes but all three species of mosquitoes partition the resource in space and time. When mosquito larvae were forced to coexist in natural tree holes at limiting densities and at higher than natural levels of interspecific encounter, there was no evidence that Aedes geniculatus or Anopheles plumbeus affected pupation success, pupal weight, or development time of the other or that either Aedes geniculatus or C. torrentium affected the survivorship, pupation success, pupal weight, and biomass yield of the other. When A. geniculatus at limiting densities were forced in natural tree holes to live without or to coexist with natural or twice natural densities of P. serricornis and M. martinii, the presence, absence, or superabundance of the benthic insects did not affect pupation success or pupal weight of A. geniculatus; development time of A. geniculatus was faster when a superabundance of the benthic fauna was present. Effects of the benthic fauna on A. geniculatus are slight and the only significant interaction is facilitative, not competitive. The pattern of habitat segregation among treehole mosquitoes in southern Britain is characteristic of their respective genera and we propose that this pattern is more likely (but not certain) to have arisen through a process of independent evolution than through competitively driven niche shifts among already coexisting species.     

Particle size,resource concentration,and the distribution of net-spinning caddisflies

Summary The dimensions of net meshes constructed by hydropsychid Trichoptera vary both within and between species. Despite these catchnet differences, the diets of most Hydropsychidae studied in Utah streams were statistically indistinguishable. There was no relationship between the size of available resources and catchnet construction among species assemblages inhabiting 10 different localities. A particle-size model of caddis communities, suggesting that taxa feed selectively on particle sizes corresponding to the dimension of catchnet meshes, is not supported by these data.Diatom concentration increased regularly with downstream passage in two different drainages. The identity and number of coexisting hydropsychid species and the size of their catchnets were strongly correlated with diatom concentration. Taxa with large catchnet mesh were the only residents at sites where diatom concentration was very low; as resource concentration increased downstream, species with successively smaller mesh joined the coexisting guild. Together, the broad dietary similarities and distributional pattern from Utah streams suggest that resource concentration, rather than particle size, is the basis of community organization among the hydropsychid Trichoptera.     

Transnational migration and the redefinition of the state: Variations and explanations

In this article, we examine the shifting policies of sending country states towards communities living abroad, demonstrate the ways in which these are redefining the relationship between the state and its territorial boundaries, and highlight how these reconfigure conventional understandings of sovereignty, citizenship and membership. We begin by delineating the ­different types of policies that sending states are adapting in order to break down categories like "global nations policies" and to identify similarities and differences between states. We then suggest some possible explanations both for the convergence we see on the "repertoire" of policies that states employ and divergence we see in how far states are willing to go to ensure that migrants remain enduring long-distance membership. We draw on material from several countries, but look most closely at Brazil, Mexico, the Dominican Republic and Haiti.     

Conclusion: Towards a new world - the origins and effects of transnational activities

The preceding set of articles is reviewed with a focus on the forces affecting the rise and character of grass-roots transnationalism and its effects in countries of origin and destination. The increasing visibility of the phenomenon has led to recent attacks based on its alleged disintegrative consequences for the host society and culture. From a review of the evidence in this volume and the recent literature on immigrant adaptation, I conclude that the opposite is the case. Implications of findings presented in this collection for official policies towards transnationalism and the latter's effect on sending countries are examined.     

Ethnic conflict and the United Nations

The United Nations [UN] is an organization of states. As such it can be expected to represent the interests of its members and uphold a state‐centric view of international politics. For this reason it has been suggested that the organization cannot respond positively to ethnic conflicts within states, or across state borders. However, since such ethnic conflicts can be a threat to international peace and security and to internationally accepted norms of behaviour, the UN cannot always remain indifferent. In fact, it has become involved in ethnic conflicts in several ways. It has dispatched peace‐keeping operations to Cyprus and Lebanon, which try to keep apart the warring factions. The UN has been involved in peace‐making in ethnic conflicts through mediation and Security Council and General Assembly resolutions. It has also engaged in peace‐building, which involves efforts to change both socio‐economic conditions and the mutually hostile attitudes of the parties to violent ethnic conflict. Finally, even though the UN, unlike the League of Nations, has not been prepared to adopt a system of minority‐rights protection, it has been involved in the issue of group rights in at least three areas. These are the Genocide Convention, the work of the Sub‐Commission for the Prevention of Discrimination and the Protection of Minorities, and the issue of the right of national self‐determination.     

Review article: The peculiar institution: Patterson and Foner on slavery and abolition

Orlando Patterson, SLAVERY AND SOCIAL DEATH: A COMPARATIVE STUDY, Cambridge, Mass., Harvard University Press, 1983, 511 pp., £24.

Eric Foner, NOTHING BUT FREEDOM: EMANCIPATION AND ITS LEGACY, Baton Rouge and London, Louisiana State University Press, 1983, 142 pp., $14.95.     

Clara Law's Floating Life and Hong Kong-Australian 'flexible citizenship'

Clara Law's film Floating Life was the first Australian film to be nominated for an Oscar for Best Foreign Film, and the first Australian film to deal with migrant Hong Kong Chinese identities 'from inside'. From perspectives of transnational Chinese migration and flexible citizenship, this article looks at Floating Life as a Hong Kong Chinese migrant reading of Australia, which defamiliarizes and recontextualizes familiar Australian localities and geopolitical formations, contrasting them with the film's other principal loci of Hong Kong and Germany. It also interprets the film as a neo-Confucian study of family disintegration in a migrant context, and an exploration of notions of home and identity.     

Network epidemic models with two levels of mixing

The study of epidemics on social networks has attracted considerable attention recently. In this paper, we consider a stochastic SIR (susceptible-->infective-->removed) model for the spread of an epidemic on a finite network, having an arbitrary but specified degree distribution, in which individuals also make casual contacts, i.e. with people chosen uniformly from the population. The behaviour of the model as the network size tends to infinity is investigated. In particular, the basic reproduction number R(0), that governs whether or not an epidemic with few initial infectives can become established is determined, as are the probability that an epidemic becomes established and the proportion of the population who are ultimately infected by such an epidemic. For the case when the infectious period is constant and all individuals in the network have the same degree, the asymptotic variance and a central limit theorem for the size of an epidemic that becomes established are obtained. Letting the rate at which individuals make casual contacts decrease to zero yields, heuristically, corresponding results for the model without casual contacts, i.e. for the standard SIR network epidemic model. A deterministic model that approximates the spread of an epidemic that becomes established in a large population is also derived. The theory is illustrated by numerical studies, which demonstrate that the asymptotic approximations work well, even for only moderately sized networks, and that the degree distribution and the inclusion of casual contacts can each have a major impact on the outcome of an epidemic.     

Leaf traits and associated ecosystem characteristics across subtropical and timberline forests in the Gongga Mountains,Eastern Tibetan Plateau

Knowledge of how leaf characteristics might be used to deduce information on ecosystem functioning and how this scaling task could be done is limited. In this study, we present field data for leaf lifespan, specific leaf area (SLA) and mass and area-based leaf nitrogen concentrations (N_mass, N_area) of dominant tree species and the associated stand foliage N-pool, leaf area index (LAI), root biomass, aboveground biomass, net primary productivity (NPP) and soil available-N content in six undisturbed forest plots along subtropical to timberline gradients on the eastern slope of the Gongga Mountains. We developed a methodology to calculate the whole-canopy mean leaf traits to include all tree species (groups) in each of the six plots through a series of weighted averages scaled up from leaf-level measurements. These defined whole-canopy mean leaf traits were equivalent to the traits of a leaf in regard to their interrelationships and altitudinal trends, but were more useful for large-scale pattern analysis of ecosystem structure and function. The whole-canopy mean leaf lifespan and leaf N_mass mainly showed significant relationships with stand foliage N-pool, NPP, LAI and root biomass. In general, as elevation increased, the whole-canopy mean leaf lifespan and leaf N_area and stand LAI and foliage N-pool increased to their maximum, whereas the whole-canopy mean SLA and leaf N_mass and stand NPP and root biomass decreased from their maximum. The whole-canopy mean leaf lifespan and stand foliage N-pool both converged towards threshold-like logistic relationships with annual mean temperature and soil available-N variables. Our results are further supported by additional literature data in the Americas and eastern China.     

Patterns of vegetation and grasshopper community composition

Summary A study was conducted to evaluate differences in rangeland grasshopper communities over environmental gradients in Gallatin Valley, Montana, USA. The concept of habitat type (Daubenmire 1966) was used as a basis for discriminating between groupings of patches based on vegetation. A total of 39 patches were selected that represented five recognized grassland habitat types (Mueggler and Stewart 1980), as well as two disturbed types (replanting within a known habitat type). Repeated sampling in 1988 of both the insect and plant communities yielded a total of 40 grasshopper (19 664 individuals) and 97 plant species. Detrended Correspondence Analysis (DCA) indicated that patch classifications based on presence and percent cover of plants were appropriate and showed good between-group (habitat type) separation for patches along gradients of precipitation/elevation and plant community complexity. Results from undisturbed habitats showed that plant and grasshopper species composition changed over observed environmental gradients and suggested that habitat type influenced not only species presence, but also relative abundance. Discussion is presented that relates results with patch-use and core and satellite species paradigms.     

Floristic composition and spatial distribution assessment of montane mesophilous grasslands in the central Apennines,Italy: A multi-scale and diachronic approach

Abstract

Evaluation of past land use offers valuable information in seeking to understand the distribution patterns of plant communities, insofar as such activity may have altered soil features, causing anthropogenic soil patchiness and marked plant diversity both locally and regionally. This study sought to provide a general overview of the relationships between the different syntaxonomical units and the soil features in a sub-Mediterranean grassland landscape, starting from assessment of soil parameters. In addition, we wanted to verify whether soil features and hierarchical landscape assessments of grasslands under homogeneous grazing disturbance are sufficient to explain the floristic differentiation of the plant communities, and whether study of land use history helps explain the distribution patterns of these plant communities. A clear understanding of the relationships between environmental factors and the floristic composition of plant communities is a strong basis for future inquiries into how disturbance variations (grazing, mowing, manuring, etc.) and past land use variations have affected grassland structures. This study examined nine syntaxa that develop on semi-flat slopes or those with northern exposure.