Factors affecting immigration of adults: experimental and theoretical observations with rodents

We examined immigration in populations of Peromyscus leucopus (white-footed mice) by 1) monitoring natural immigration at 10 sites, 2) introducing experimental immigrants into eight populations, and 3) constructing qualitative models of immigration. Density of natural immigrants covaried positively with resident density, and successful assimilation was lower at low resident and immigrant densities. Females and males did not differ in their chance of achieving residency. Year, sex, and number introduced were significant predictors of assimilation by individuals. Experimentally introduced individuals had no effect on densities of those mice resident before the introductions. Results obtained from studying natural immigration differed from those obtained from studying experimental immigration. Signed digraphs and time averaging were used to model the consequences of different resident-immigrant relationships and to suggest how different sources of variation may have affected assimilation and led to differences in natural and experimental immigration. Resident and immigrant densities could have been positively correlated even if residents actively inhibited immigration. Variation in immigrant density and survival rather than resident territorial activity apparently determined patterns of assimilation.     

Setting “Spanish legacies” into further context: some findings and thoughts from CILS4EU

This contribution compares some major findings of “Spanish Legacies” to findings from the CILS4EU study that has been conducted in four other European countries. Despite the differences in the immigration history and the composition of the immigrant youth, basic results of psychosocial adaptation are surprisingly similar for England, Germany, the Netherlands, and Sweden. This confirms the mostly optimistic picture of the future of the second generation in Europe as drawn for Spain. In a sense, the similarities suggest that the role of the receiving context might be less important than is expected in overarching theoretical frameworks such as “segmented assimilation”. Some aspects of integration that are not covered in “Spanish Legacies” could raise more doubts on the smoothness of the adaptation processes for some immigrants groups.     

Consequences of recurrent gene flow from crops to wild relatives

Concern about gene flow from crops to wild relatives has become widespread with the increasing cultivation of transgenic crops. Possible consequences of such gene flow include genetic assimilation, wherein crop genes replace wild ones, and demographic swamping, wherein hybrids are less fertile than their wild parents, and wild populations shrink. Using mathematical models of a wild population recurrently receiving pollen from a genetically fixed crop, we find that the conditions for genetic assimilation are not stringent, and progress towards replacement can be fast, even for disfavoured crop genes. Demographic swamping and genetic drift relax the conditions for genetic assimilation and speed progress towards replacement. Genetic assimilation can involve thresholds and hysteresis, such that a small increase in immigration can lead to fixation of a disfavoured crop gene that had been maintained at a moderate frequency, even if the increase in immigration is cancelled before the gene fixes. Demographic swamping can give rise to 'migrational meltdown', such that a small increase in immigration can lead to not only fixation of a disfavoured crop gene but also drastic shrinkage of the wild population. These findings suggest that the spread of crop genes in wild populations should be monitored more closely.     

Welcome to the Club?: A response to The Cross -Border Connection by Roger Waldinger

Roger Waldinger's provocative book on migrants’ cross-border lives corroborates many insights already established by transnational migration scholarship. He makes a compelling case for the need to understand migration not just as assimilation – neo, segmented, or otherwise – but also as about how people continue to be simultaneously involved in their homelands, the countries where they settle, and other salient places. I am glad that Waldinger has lent his voice to correct the unproductive divide between immigration and emigration scholarship. But the ‘new’ path he charts forward to right what he sees as wrong with current scholarship is, at times, so selectively formulated and argued that it undercuts its effectiveness.     

A comparativist manifesto for international migration studies

Abstract

Drawing on thirteen years of fieldwork among Mexican migrants in the United States and Mexico and comparisons of immigration policy throughout the Americas, this paper systematically elaborates the advantages and disadvantages of different kinds of multi-sited studies. A reformed logic of the Millian methods of agreement and difference takes into account the causal connections among the cases. I call for a ‘homeland dissimilation’ perspective and comparisons of internal and international migration as a way to take off the self-imposed national blinders that pre-determine many of the conclusions of the assimilation and even transnationalism literatures.     

Gendered segmented assimilation: earnings trajectories of African immigrant women and men

Racial stratification in immigrant earnings has been widely influential in theories of immigrant socioeconomic assimilation, but discussions of how racial stratification might differ by gender are underdeveloped. Segmented assimilation theory attempts to explain the underlying mechanisms that cause racial disparities, but it fails to incorporate gendered dynamics like occupational sex segregation and the feminization of particular labour flows. In this paper, we address that gap. Using data from the 1990 decennial census and the American Community Survey in 2009–11, we compare the earnings of black and white African migrants to US-born blacks and whites separately by gender. Our findings indicate that black African migrant women experience no racial disadvantage in their earnings, but black African migrant men do. Our results highlight the importance of examining racial differences in immigrant earnings interacting with gender.     

From ethnic minorities to ethnic majority policy: Multiculturalism and the shift to assimilationism in the Netherlands

Abstract

Recently in numerous European countries of immigration, there has been a widespread ‘moral panic’ about immigrants and ethnic diversity. In The Netherlands, a backlash has occurred in policy and in public discourse, with migrants being blamed for not meeting their responsibility to integrate and for practising ‘backward religions’. Why is it that a self-defined ‘liberal’ and ‘tolerant’ society demands conformity, compulsion and introduces seemingly undemocratic sanctions towards immigrants in a move towards assimilationism? These issues are analysed by providing an overview of modes of incorporation of immigrants in the Netherlands and it presents evidence on the socio-economic situation of immigrants. The article argues that patterns of disadvantage cannot be explained solely by the low human capital attributes of the original immigrants. In spite of multiculturalism, the causes have to be sought in pervasive institutional discrimination and the persistence of a culture of racism. The study argues that a shift to assimilation is more likely to create further societal divisions.     

If hippopotamuses cannot swim,how did they colonize islands?

Owing to their aquatic lifestyle, hippopotamuses are normally believed to have reached islands by swimming. Yet, some studies suggest they cannot swim due to their relatively high density. If so, this raises the question of how hippopotamuses would have reached some islands. Their immigration into the British Isles, Sicily, Malta, Zanzibar and Mafia can be accounted for, because these islands sit on continental shelves and were often linked to the mainland during the Pleistocene glacio‐eustatic sea‐level falls. In contrast, their occurrence in Crete, Cyprus and Madagascar would be more difficult to explain. Available geological evidence does not seem to rule out that the latter islands might have been connected with the nearest mainland areas in very recent times. This study intends to consider possibilities about how hippopotamuses reached islands and to show that more effective collaboration is required among specialists involved with the study of insular evolution, colonization and speciation.     

Do Migrants Degrade Coastal Environments? Migration,Natural Resource Extraction and Poverty in North Sulawesi,Indonesia

Recent literature on migration and the environment has identified key mediating variables such as how migrants extract resources from the environment for their livelihoods, the rate and efficiency of extraction, and the social and economic context within which their extraction occurs. This paper investigates these variables in a new ecological setting using data from coastal fishing villages in North Sulawesi, Indonesia. We do not find as many differences between migrant and non-migrant families regarding destructive fishing behavior, technology, and investment as might have been expected from earlier theories. Instead, the context and timing of migrant assimilation seems to be more important in explaining apparent associations of migration and environmental impacts than simply migrants themselves. This finding fits well with recent literature in the field of international migration and immigrant incorporation.     

A spotlight on “established”, as opposed to “newcomer”, Americans

By elaborating upon the idea of “relational assimilation”, Tomas Jimenez alters the dominant lens through which social scientists, and especially sociologists, have understood the concept of assimilation and the effects of immigration. In this highly readable and thoughtful book, we are asked to conceive of this kind of assimilation as one which involves “the give-and-take of adjustment”, not just a one-way route by which “newcomers” must adapt to settings populated by “established” members of the population. According to the author, ongoing forms of immigration and its resulting diversity actually change the regional self-understandings of those who are already living in those settings.     

Compelling culture: The rhetoric of assimilation among Samoan migrants in the United States

Studies of assimilation tend to focus on whether or not members of a migrant group are adjusting to their new surroundings. This article inverts this focus, asking not how migrant groups adjust, but rather how migrant groups use the language of assimilation to explain generation gaps and other exigencies of migration. This inversion sheds light on the ways a migrant group's epistemological assumptions underlie their understandings of cultural identity, and shape how they might respond to dilemmas caused by migration. Building upon ethnographic fieldwork among Samoan migrants in the United States, the article explores how and why community workers use the rhetoric of assimilation to teach Samoan parents how to raise children in the US context.     

Second‐generation decline: Scenarios for the economic and ethnic futures of the post‐1965 American immigrants

‘Second‐generation decline’ questions the current American faith in the myth of nearly automatic immigrant success. In discussing economic scenarios, positive and negative, for the future of the children of the post‐1965 immigrants, the possibility is proposed that a significant number of the children of poor immigrants, especially dark‐skinned ones, might not obtain jobs in the mainstream economy. Neither will they be willing ‐ or even able ‐ to take low‐wage, long‐hour ‘immigrant’ jobs, as their parents did. As a result, they (and young males among them particularly) may join blacks and Hispanics among those already excluded, apparently permanently, from the mainstream economy. The article also deals with the relations between ethnicity and economic conditions in the USA and with the continued relevance of the assimilation and acculturation processes described by ‘straight‐line theory’. This issue, as well as most others discussed, may also be salient for European countries experiencing immigration, especially those countries with troubled economies.     

Nonmarital Fertility, Family Structure, and the Early School Achievement of Young Children from Different Race/Ethnic and Immigration Groups

Working from a life course perspective, this study examined the links between mothers' fertility and relationship statuses and children's early school achievement and how these links varied by race/ethnicity and immigration status. Analyses of nationally representative data from the Early Childhood Longitudinal Study-Kindergarten Cohort revealed that children born to unmarried women scored lower than children of married women on math tests in kindergarten and first grade. This pattern was most attributable to associated differences in family income and parent education, and it was moderated by women's marital and relationship statuses after having their children. Evidence also suggested that the academic risks of some family structure pattern relative to continuously married parents might have been more pronounced for White children.     

Immigration and Chinese reproductive behavior in Canada

This study is intended to provide an empirical testing of the minority status hypothesis with regard to the fertility behavior of Chinese immigrants to Canada. The focus is placed on the role of group or social context on actions of individuals. Factors incurred in the immigration process as explained by disruption and assimilation hypotheses are also examined. Using the multi-level contextual analysis, we have found that the relative economic insecurity that comes from minority membership and the course of immigration serves to decrease fertility of minority members, whether they are associated with a pronatalist heritage or not. However, pronatalist traditions do stimulate fecundity of Chinese immigrants as long as their relative economic status is improved and the hardship is gone.     

Ethnicity,reception and the growth of American immigration

Deportation has always been a feature of the American political, social and economic discourse. A twin effect of immigration, deportation concerns who is granted the right to stay and who is removed from the country. Amid the growing debate on reform, this essay casts light on the changing nature of deportation law during the last century. Paying attention to the reception which immigrants receive and the perceptions of threat and economic competition which natives often perceive, this work evaluates how policy has shifted in response to the changing face of newcomers. As immigration law becomes intertwined with criminal law, so do the stipulations governing entry and exit. Within a politically charged social space, American immigration is a story punctuated with racialized and criminalized images of immigrants. Bridging ethnic and racial currents, this work seeks to understand how these effects continue to shape contemporary immigration policy.     

Regulation of plant nitrate assimilation: from ecophysiology to brain proteins

Nitrogenous inorganic compounds impact plants as nutrients, signals and toxins. We are dissecting a regulatory network that controls nitrate assimilation at the level of nitrate reductase (NR) activity. The identification of protein kinase cascades, protein phosphatases and 14-3-3 proteins as regulators of NR are giving clues about how plants sense their nutrient availability, and use the information to signal changes in their metabolism and developmental strategies to cope with supplies. We hope that understanding these controls might lead to the design of transgenic plants with deregulated signalling networks, which would make them more efficient in using nitrogen fertilizers, and improving quality and yield of crops. There are circumstantial indications that gaseous anthropogenic nitrogenous emissions might also have complex regulatory influences on plant growth and development.     

Exploring the views on hunting of Spanish hunters: effect of age and public vs. anonymous opinions

We explored the views held by Spanish hunters on hunting, and assessed how these views varied according to participant characteristics and whether or not the responses were made public via a hunter’s magazine. Hunters expressed many positive values in relation to hunting, but were critical of their own community as well as other stakeholders. Spanish hunters felt misunderstood and even attacked by society at large. There was also a widespread negative perception of the future of hunting. The frequency of references to different opinions varied between anonymous and public respondents and in relation to age group. Participants who expressed their opinions publicly mentioned the ecological values of hunting more frequently, were more critical towards their own community, and viewed the future of hunting more positively than anonymous participants. This may indicate an intended projected positive image; namely, Spanish hunters may publicly emphasize those views that improve their position in society.     

Building blocks of the apoptotic pore: how Bax and Bak are activated and oligomerize during apoptosis

The central role of the Bcl-2 family in regulating apoptotic cell death was first identified in the 1980s. Since then, significant in-roads have been made in identifying the multiple members of this family, characterizing their form and function and understanding how their interactions determine whether a cell lives or dies. In this review we focus on the recent progress made in characterizing the proapoptotic Bcl-2 family members, Bax and Bak. This progress has resolved longstanding controversies, but has also challenged established theories in the apoptosis field. We will discuss different models of how these two proteins become activated and different ‘modes'' by which they are inhibited by other Bcl-2 family members. We will also discuss novel conformation changes leading to Bak and Bax oligomerization and speculate how these oligomers might permeabilize the mitochondrial outer membrane.     

Smoking at the workplace: effects of genetic and environmental causal accounts on attitudes toward smoking employees and restrictive policies

People hold diverse beliefs regarding the etiologies of individual and group differences in behaviors which, in turn, might affect their attitudes and behaviors. It is important to establish how perceived etiologies of smoking might affect the effectiveness of policy initiatives and prevention efforts. The present study assessed whether exposure to genetic vs. environmental accounts for smoking affects attitudes toward (a) workplace-related smoking policies and (b) smokers at the workplace. Results indicate that exposure to a genetic explanation led to stronger objections to a smoking restrictive policy compared with a non-genetic explanation. Additionally, participants in the genetic condition were more accepting of a smoker in the workplace than those in the environmental condition. Evidently, beliefs about the etiology of smoking influence a range of attitudes related to smokers and smoking-related policies.