Recreational mobilities in (and beyond) the compact city

What happens if one takes recreational mobilities as a point of departure for making sense of the compact city? This special issue offers interdisciplinary explorations of how one might approach studies of cities and metropolitan regions in new ways, using recreational mobilities as both lens and focal point. In so doing, the contributions aim to advance recreational mobilities as a critical theme for scholarship and practice. We specifically hope to demonstrate how such an approach is fruitful for grappling with the legacies of rationalism and modernism in spatial planning, with a focus on the contemporary ideal of the 'compact city' as both phenomenon and normative impulse that has come to dominate discourses of urban design and urban planning in recent decades.(1

Gene expression plasticity across hosts of an invasive scale insect species

For plant-eating insects, we still have only a nascent understanding of the genetic basis of host-use promiscuity. Here, to improve that situation, we investigated host-induced gene expression plasticity in the invasive lobate lac scale insect, Paratachardina pseudolobata (Hemiptera: Keriidae). We were particularly interested in the differential expression of detoxification and effector genes, which are thought to be critical for overcoming a plant's chemical defenses. We collected RNA samples from P. pseudolobata on three different host plant species, assembled transcriptomes de novo, and identified transcripts with significant host-induced gene expression changes. Gene expression plasticity was pervasive, but the expression of most detoxification and effector genes was insensitive to the host environment. Nevertheless, some types of detoxification genes were more differentially expressed than expected by chance. Moreover, we found evidence of a trade-off between expression of genes involved in primary and secondary metabolism; hosts that induced lower expression of genes for detoxification induced higher expression of genes for growth. Our findings are largely consonant with those of several recently published studies of other plant-eating insect species. Thus, across plant-eating insect species, there may be a common set of gene expression changes that enable host-use promiscuity

Egenuppsatta vägskyltar â Ett exempel på visuell vägkantsinteraktion

Syftet med denna uppsats är att lyfta fram visuell vägkantsinteraktion i form av egenuppsatta skyltar som ett vardagligt socialt fenomen på vägen, samt att diskutera olika betydelser av denna typ av kommunikation. Med hjälp av fotografier och intervjumaterial diskuteras skyltarnas koppling till trafik och de platser där de står. Detta följs av en analys av hur relationen mellan avsändare och väganvändare etableras, definieras, tolkas och avgränsas genom dessa skyltar. Dessutom behandlas skyltarnas flexibla, ibland kortvariga, giltighet. Slutligen diskuteras vår förståelse av vägen utifrån dessa informella vägskyltar

Fyrkantifieringen av handeln

This article addresses the squarification of Swedish retailing in the 1960- and 1970’s through an analysis of a Swedish packaging magazine. Starting with the geometric shape (round, triangular or square) of and corresponding cell (cuboids, cubes, cones, pyramids or cylinders) of milk packages we analyze how the square shape gradually became dominant. The transformation was not limited to the package itself, but included products, store layouts, handling equipment, staff, consumers and consumption as well as the transport of goods from the store to the home. Thus, these changes lead to an pervasive transformation of retailing and consumption from round to square, a development that probably has not yet ended

Modeling Cell Gradient Sensing and Migration in Competing Chemoattractant Fields

Directed cell migration mediates physiological and pathological processes. In particular, immune cell trafficking in tissues is crucial for inducing immune responses and is coordinated by multiple environmental cues such as chemoattractant gradients. Although the chemotaxis mechanism has been extensively studied, how cells integrate multiple chemotactic signals for effective trafficking and positioning in tissues is not clearly defined. Results from previous neutrophil chemotaxis experiments and modeling studies suggested that ligand-induced homologous receptor desensitization may provide an important mechanism for cell migration in competing chemoattractant gradients. However, the previous mathematical model is oversimplified to cell gradient sensing in one-dimensional (1-D) environment. To better understand the receptor desensitization mechanism for chemotactic navigation, we further developed the model to test the role of homologous receptor desensitization in regulating both cell gradient sensing and migration in different configurations of chemoattractant fields in two-dimension (2-D). Our results show that cells expressing normal desensitizable receptors preferentially orient and migrate toward the distant gradient in the presence of a second local competing gradient, which are consistent with the experimentally observed preferential migration of cells toward the distant attractant source and confirm the requirement of receptor desensitization for such migratory behaviors. Furthermore, our results are in qualitative agreement with the experimentally observed cell migration patterns in different configurations of competing chemoattractant fields

Pneumolysin binds to the mannose receptor C type 1 (MRC-1) leading to anti-inflammatory responses and enhanced pneumococcal survival

Streptococcus pneumoniae (the pneumococcus) is a major cause of mortality and morbidity globally, and the leading cause of death in children under 5 years old. The pneumococcal cytolysin pneumolysin (PLY) is a major virulence determinant known to induce pore-dependent pro-inflammatory responses. These inflammatory responses are driven by PLY–host cell membrane cholesterol interactions, but binding to a host cell receptor has not been previously demonstrated. Here, we discovered a receptor for PLY, whereby pro-inflammatory cytokine responses and Toll-like receptor signalling are inhibited following PLY binding to the mannose receptor C type 1 (MRC-1) in human dendritic cells and mouse alveolar macrophages. The cytokine suppressor SOCS1 is also upregulated. Moreover, PLY–MRC-1 interactions mediate pneumococcal internalization into non-lysosomal compartments and polarize naive T cells into an interferon-γlow, interleukin-4high and FoxP3+ immunoregulatory phenotype. In mice, PLY-expressing pneumococci colocalize with MRC-1 in alveolar macrophages, induce lower pro-inflammatory cytokine responses and reduce neutrophil infiltration compared with a PLY mutant. In vivo, reduced bacterial loads occur in the airways of MRC-1-deficient mice and in mice in which MRC-1 is inhibited using blocking antibodies. In conclusion, we show that pneumococci use PLY–MRC-1 interactions to downregulate inflammation and enhance bacterial survival in the airways. These findings have important implications for future vaccine design

Submarine Fernandina : magmatism at the leading edge of the Galapagos hot spot

Author Posting. © American Geophysical Union, 2006. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 7 (2006): Q12007, doi:10.1029/2006GC001290.New multibeam and side-scan sonar surveys of Fernandina volcano and the geochemistry of lavas provide clues to the structural and magmatic development of Galápagos volcanoes. Submarine Fernandina has three well-developed rift zones, whereas the subaerial edifice has circumferential fissures associated with a large summit caldera and diffuse radial fissures on the lower slopes. Rift zone development is controlled by changes in deviatoric stresses with increasing distance from the caldera. Large lava flows are present on the gently sloping and deep seafloor west of Fernandina. Fernandina's submarine lavas are petrographically more diverse than the subaerial suite and include picrites. Most submarine glasses are similar in composition to aphyric subaerially erupted lavas, however. These rocks are termed the “normal” series and are believed to result from cooling and crystallization in the subcaldera magma system, which buffers the magmas both thermally and chemically. These normal-series magmas are extruded laterally through the flanks of the volcano, where they scavenge and disaggregate olivine-gabbro mush to produce picritic lavas. A suite of lavas recovered from the terminus of the SW submarine rift and terraces to the south comprises evolved basalts and icelandites with MgO = 3.1 to 5.0 wt.%. This “evolved series” is believed to form by fractional crystallization at 3 to 5 kb, involving extensive crystallization of clinopyroxene and titanomagnetite in addition to plagioclase. “High-K” lavas were recovered from the southwest rift and are attributed to hybridization between normal-series basalt and evolved-series magma. The geochemical and structural findings are used to develop an evolutionary model for the construction of the Galápagos Platform and better understand the petrogenesis of the erupted lavas. The earliest stage is represented by the deep-water lava flows, which over time construct a broad submarine platform. The deep-water lavas originate from the subcaldera plumbing system of the adjacent volcano. After construction of the platform, eruptions focus to a point source, building an island with rift zones extending away from the adjacent, buttressing volcanoes. Most rift zone magmas intrude laterally from the subcaldera magma chamber, although a few evolve by crystallization in the upper mantle and deep crust.This work was supported by the National Science Foundation grants OCE0002818 and EAR0207605 (D.G.), OCE0002461 (D.J.F. and M.K.), OCE9811504 (D.J.F. and M.R.P.), and EAR0207425 (K.H.) and WHOI postdoctoral support for Soule