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Although there is no consensus on the definition of the peri-urban interface, there is growing recognition among development professionals and institutions that rural and urban features tend increasingly to co-exist within cities and beyond their limits. There is also recognition that the urban-rural dichotomy that is deeply ingrained in planning systems is inadequate for dealing with processes of environmental and developmental change in the peri-urban context. This paper argues that environmental planning and management of the peri-urban interface cannot simply be based on the extrapolation of planning approaches and tools applied in rural and urban areas. Instead, it needs to be based on the construction of an approach that responds to the specific environment, social, economic and institutional aspects of the peri-urban interface. The paper also outlines approaches to environmental planning and management in the peri-urban interface, examining its specificity in terms of both the challenges faced and possible approaches for implementation.

Summary The concept of urban metabolism, referring to the exchange processes that produce the urban environment, has inspired new ways of thinking about how cities can be made sustainable and has also raised criticisms about the specific social and economic arrangements in which some forms of flow are prioritized or marginalized within the city. This article explores how the concept of urban metabolism travels across disciplines, using a comparative analysis of different approaches to urban metabolism within industrial ecology, urban ecology, ecological economics, political economy and political ecology. The analysis reveals six main themes emerging within interdisciplinary boundaries in relation to urban metabolism, and how this concept enables new understandings of (1) the city as an ecosystem, (2) material and energy flows within the city, (3) economic–material relations within the city, (4) economic drivers of rural–urban relationships, (5) the reproduction of urban inequality, and (6) attempts at resignifying the city through new visions of socioecological relationships. The article suggests potential areas for cross‐disciplinary synergies around the concept of urban metabolism and opens up avenues for industrial ecology to engage with the politics and the governance of urban development by examining the city and its metabolism.

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Significant lessons can be drawn from grassroots experiences of coping with extreme weather for reducing the vulnerability of the urban poor to climate change. This paper examines the household and community coping strategies used by low-income households living in Korail, the largest informal settlement in Dhaka. This includes how they use physical, economic and social means to reduce risk, reduce losses and facilitate recovery from flooding and high temperatures, and shows how grassroots adaptation differs according to the level of risk from flooding. The paper also discusses how local planning and governance mechanisms aimed at adaptation can support these coping strategies, including mainstreaming them into adaptation plans that can be scaled up to the citywide level.

Using the results of a comparative three-year research project in five metropolitan areas, this article reviews a range of practices in accessing water and sanitation by peri-urban poor residents and producers. It starts from the observation that neither centralized supply policies nor the market through, for example, large-scale profit-making enterprises are able to meet their needs. Although they are consumers insofar as they have no option but to pay market prices for water (and often for sanitation), the peri-urban poor are, in practice, sometimes regarded as citizens with basic entitlements such as the right to water. This article outlines a conceptual distinction between “policy-driven” and “needs-driven” practices in the access to peri-urban water and sanitation services. The case studies show that this access is mainly needs-driven and informal rather than the result of formal policies. The key to structural improvements in water and sanitation lies in the recognition of these practices and their articulation to the formal system under new governance regimes.

Rapid urbanization in the global South is adding epidemiological and nutritional challenges and increasing disease and health burdens for citizens. Greater movement of people, animals, food and trade often provides favourable grounds for the emergence of infectious diseases, including zoonoses. We conduct a rapid evidence scan to explore what is known and hypothesized about the links between urbanization and zoonosis emergence. This points to rapid demographic growth, migration and density, increased movement of people and animals, and changes in land uses as the main processes linked to the prevalence of zoonosis in the urban global South. We argue that this emerging global health challenge is also deeply connected with the urbanization of poverty and inequalities within cities. Tackling the micro-level causal relationships between urbanization and zoonosis requires urgent attention to living conditions, as well as the wider socioenvironmental transitions and structural drivers that produce and reproduce risk accumulation in urban settings.

Essential thrombocythemia (ET) is heterogeneous with respect to natural history, Xchromosome inactivation patterns (XCIPs), and presence of the V617F mutation in Janus kinase 2 (JAK2). We studied 111 patients with ET; 39% were JAK2 mutant positive, and clone size (percentage mutant JAK2) was concordant with XCIP when constitutive T-cell patterns were taken into account. JAK2 mutant clones were present in both clonal and polyclonal cases as determined by XCIP, and the former had higher mutant JAK2 levels (median 26% versus 16%; P ‫؍‬ .001). No change was observed in serial XCIP analysis of 14 polyclonal patients over a median follow-up of 61 months. Furthermore, 18 of 19 mutant-positive patients showed no significant change in mutant JAK2 level over a median follow-up of 47 months. These results suggest that, in many cases of ET, a small stable clone containing a JAK2 mutation can be maintained as a subpopulation for many years. IntroductionPatients with essential thrombocythemia (ET) show biologic heterogeneity. Although initially considered to be a clonal disease, studies using X-chromosome inactivation patterns (XCIPs) in females have demonstrated that, once constitutional and ageacquired skewing have been taken into account, a significant proportion of patients have polyclonal myelopoiesis, 1-5 although this does not exclude the presence of minor clones. More recently, the V617F mutation in Janus kinase 2 (JAK2) has been reported in a variable proportion of patients with ET (23%-72%, depending on method used), [6][7][8][9][10][11][12][13] and is present in patients with both clonal and polyclonal XCIPs. [11][12][13] The latter observation suggests that minor clones could arise on a polyclonal background and then gradually be selected over time to lead to evident clonality. We have used longitudinal studies to address this issue. Patients, materials, and methods Patients and samplesApproval for these studies was provided by the London Multi-center Research Ethics Committee. Patient consent was obtained according to the Declaration of Helsinki. Peripheral blood samples were obtained from 111 patients with ET (92 female, 19 male). Neutrophils and CD3 ϩ cells were purified and DNA prepared as previously described. 2 XCIPsThe human androgen receptor assay (HUMARA) was performed as previously described, 2 except using a fluorescent-labeled primer, and analysis was done on the Beckman Coulter CEQ8000 Genetic Analysis System (Beckman Coulter, Fullerton, CA). Results are given as the mean relative percentage of the smaller and larger alleles (A%:B%), respectively.There are several caveats to interpretation of an XCIP 14 and a pattern was only considered to be truly clonal if (1) the myeloid cell XCIP showed more than 75% of one of the X-alleles, (2) there was more than 20% difference between the XCIP of T cells (reflecting the constitutional hemopoietic stem cell pattern) and myeloid cells, and (3) the individual was younger than 65 years of age. JAK2 mutation analysisDNA was screened for presence of the G-to-T JAK2 ...