New lower bounds for the second variable Zagreb index

The aim of this paper is to obtain new sharp inequalities for a large family of topological indices, including the second variable Zagreb index \(M_2^{\alpha }\), and to characterize the set of extremal graphs with respect to them. Our main results provide lower bounds on this family of topological indices involving just the minimum and the maximum degree of the graph. These inequalities are new even for the Randi?, the second Zagreb and the modified Zagreb indices.     

Coopetition in coworking-spaces: value creation and appropriation tensions in an entrepreneurial space

Coopetition has the potential to improve entrepreneurship and innovation. It will be prevalent in coworking-spaces building a growing field for individual and corporate entrepreneurship. The individuals’ physical closeness in the professional and social space of the coworking-space eases multifaceted transfers of explicit and implicit knowledge, stimulating creation, transfer, overhaul, and implementation of entrepreneurial ideas. While entrepreneurs in these coworking-spaces collaborate on sharing knowledge and resources and on finding creative ideas from which can breed new venture concepts, they simultaneously compete on the appropriation of values. Thus, entrepreneurs in coworking-spaces face coopetitive tensions of creating and appropriating the values. Based  on  interview data and secondary sources, this paper explains four different prototype institutions of coworking-spaces: the corporate coworking-space, the open corporate coworking-space, the consultancy coworking-space, and the independent coworking-space. Study explains different tensions of value creation and appropriation that occur within the coopetition in the different forms of coworking-spaces.     

Modelling period fertility: Schooling and intervals following a birth in Eastern Africa

We describe a regression-based approach to the modelling of age-, order-, and duration-specific period fertility, using retrospective survey data. The approach produces results that are free of selection biases and can be used to study differential fertility. It is applied to Demographic and Health Survey data for Ethiopia, Kenya, Tanzania, and Zimbabwe to investigate differential trends in fertility by education. Parity progression fell and the intervals following each birth lengthened between the 1970s and 2000s in all four countries. Fertility fell most among women with secondary education. In contrast to other world regions, postponement of successive births for extended periods accounted for much of the initial drop in fertility in these African countries. However, family size limitation by women with secondary education in Ethiopia and Kenya and longer birth spacing in Zimbabwe also played significant roles. Thus, birth control is being adopted in Eastern Africa in response to diverse changes in fertility preferences.     

Occupational closure and immigrant entrepreneurship: Russian Jews in Israel

The recent wave of Jews emigrating from countries of the former Soviet Union to Israel has created structural conditions for immigrant entrepreneurship. The large size of the migrant population and its spatial concentration create a demand for services and products that can be provided by immigrants. This paper investigates the factors associated with intentions to open a small business in a sample of Jewish immigrants from the countries of the former Soviet Union. It was found that intentions to open a small business are related to previous business experience, education, income, and length of residence in the country. Immigrants become interested in entrepreneurship after learning that their prospects of finding a job in their profession are meager and explain their motivation to open a small business as being to increase their income. The findings seem to support the disadvantage theory that conceptualizes entrepreneurship as an adaptive mechanism to structural barriers in the primary labor market that create an occupational closure for immigrants possessing low and middle levels of education and income.     

Protected areas in the periphery: Conservation and controversy in northern Scotland

Controversies arising from the notification of large areas of land as Sites of Special Scientific Interest in northern Scotland are reviewed against the background of surveys of land occupiers' experiences on the one hand, and of trends in conservation thinking in the wider world on the other. Most of the protected area is of low capability for productive land use, and there is little evidence of adverse trends in labour and employment on SSSIs compared with similar, non-SSSI land. Site designation has in practice impeded land management in the cases of relatively few land occupiers, but rather more have negative attitudes towards it. It is concluded that some elements of the ‘scientific colonialism’ model of protected areas can be detected.     

Knox meets Cox: Adapting epidemiological space-time statistics to demographic studies

Many important questions and theories in demography focus on changes over time, and on how those changes differ over geographic and social space. Space-time analysis has always been important in studying fertility transitions, for example. However, demographers have seldom used formal statistical methods to describe and analyze time series of maps. One formal method, used widely in epidemiology, criminology, and public health, is Knox’s space-time interaction test. In this article, we discuss the potential of the Knox test in demographic research and note some possible pitfalls. We demonstrate how to use familiar proportional hazards models to adapt the Knox test for demographic applications. These adaptations allow for nonrepeatable events and for the incorporation of structural variables that change in space and time. We apply the modified test to data on the onset of fertility decline in Brazil over 1960–2000 and show how the modified method can produce maps indicating where and when diffusion effects seem strongest, net of covariate effects.     

Climate change and population migration in Brazil’s Northeast: scenarios for 2025–2050

This research contributes to an understanding of the relationship between climate change, economic impacts and migration. We model the long-term relationship (up to 45 years of projection) between demographic dynamics—particularly migration—driven by changes in the performance of the economy due to climate changes in the Northeast region of Brazil. The region is of particular relevance to the study of climate change impacts given its large human population (28% of Brazil’s population) and high levels of impoverishment, having an extensive semi-dry area which will be severely impacted by growing temperatures. Ultimately, the integrated model generates state- and municipal-level migration scenarios based on climate change impacts on the primary economic sectors and their articulations with other sectors. Results suggest that the predicted climate changes will impact severely the agriculture sector in the region, acting as a potential migration push factor to other regions in the country. Finally, we discuss how the increased vulnerability of some groups, particularly migrants, can be factored into Brazilian public policy and planning.     

The effects of gender on climate change knowledge and concern in the American public

This study tests theoretical arguments about gender differences in scientific knowledge and environmental concern using 8 years of Gallup data on climate change knowledge and concern in the US general public. Contrary to expectations from scientific literacy research, women convey greater assessed scientific knowledge of climate change than do men. Consistent with much existing sociology of science research, women underestimate their climate change knowledge more than do men. Also, women express slightly greater concern about climate change than do men, and this gender divide is not accounted for by differences in key values and beliefs or in the social roles that men and women differentially perform in society. Modest yet enduring gender differences on climate change knowledge and concern within the US general public suggest several avenues for future research, which are explored in the conclusion.     

Changing effects of family background on transitions to secondary education in the Netherlands: Consequences of educational expansion and reform

Recent developments in educational transitions research suggest a decomposition of qualitative dimensions within educational levels that are (nearly) universal. However, research on long-term trends of social stratification in the structurally tracked educational system of the Netherlands has not been published previously. In the Netherlands, the secondary educational level is divided into four hierarchical tracks which each lead to different options for subsequent educational decisions. A rapid increase of participation in the higher tracks over time however, may have changed the background-specific distribution of early track placement. This paper improves upon previous research on educational inequality by incorporating a long-term perspective into tracking research. The secondary level of the Dutch educational system is decomposed into its four tracks, using a time frame that covers cohorts that entered secondary education between 1946 and 1998. The application of multinomial logit regressions reveals that the choice of a secondary track is strongly depending on social background features, measured as education of the parents and occupational status of the father. We found linear downward trends of effects for fathers’ occupation in the intermediate tracks for the cohorts that entered secondary education between WWII and the 90s. The effects of parental education also decrease after WWII, but the trend is curvilinear and not enduring. Unexpectedly, the effects almost reach their previous level in the youngest cohort. Our results furthermore suggest that a controversial reform of the educational system in 1968 neither triggered nor accelerated equalization of secondary education, although it resulted in a growth of participation in senior general education (HAVO).