A Small World Perspective on Urban Systems

The theory of small-world networks as initiated by Watts and Strogatz (1998) has drawn new insights in spatial analysis as well as systems theory. The theoryâeuro?s concepts and methods are particularly relevant to geography, where spatial interaction is mainstream and where interactions can be described and studied using large numbers of exchanges or similarity matrices. Networks are organized through direct links or by indirect paths, inducing topological proximities that simultaneously involve spatial, social, cultural or organizational dimensions. Network synergies build over similarities and are fed by complementarities between or inside cities, with the two effects potentially amplifying each other according to the âeurooepreferential attachmentâeuro hypothesis that has been explored in a number of different scientific fields (Barabási, Albert 1999; Barabási A-L 2002; Newman M, Watts D, Barabàsi A-L). In fact, according to Barabási and Albert (1999), the high level of hierarchy observed in âeurooescale-free networksâeuro results from âeurooepreferential attachmentâeuro, which characterizes the development of networks: new connections appear preferentially close to nodes that already have the largest number of connections because in this way, the improvement in the network accessibility of the new connection will likely be greater. However, at the same time, network regions gathering dense and numerous weak links (Granovetter, 1985) or network entities acting as bridges between several components (Burt 2005) offer a higher capacity for urban communities to benefit from opportunities and create future synergies. Several methodologies have been suggested to identify such denser and more coherent regions (also called communities or clusters) in terms of links (Watts, Strogatz 1998; Watts 1999; Barabási, Albert 1999; Barabási 2002; Auber 2003; Newman 2006). These communities not only possess a high level of dependency among their member entities but also show a low level of âeurooevulnerabilityâeuro, allowing for numerous redundancies (Burt 2000; Burt 2005). The SPANGEO project 2005âeuro"2008 (SPAtial Networks in GEOgraphy), gathering a team of geographers and computer scientists, has included empirical studies to survey concepts and measures developed in other related fields, such as physics, sociology and communication science. The relevancy and potential interpretation of weighted or non-weighted measures on edges and nodes were examined and analyzed at different scales (intra-urban, inter-urban or both). New classification and clustering schemes based on the relative local density of subgraphs were developed. The present article describes how these notions and methods contribute on a conceptual level, in terms of measures, delineations, explanatory analyses and visualization of geographical phenomena.

Low-Cost Rural Surface Alternatives: Literature Review and Recommendations, TR-632, 2013

Freezing and thawing action induces damage to unbound gravel roads in Iowa resulting in maintenance costs for secondary road departments. Some approaches currently used by County Engineers to deal with this problem include temporarily spreading rock on the affected areas, lowering or improving drainage ditches, tiling, bridging the area with stone and geosynthetic covered by a top course of aggregate or gravel, coring boreholes and filling them with calcium chloride to melt lenses and provide drainage, and re-grading the crown to a slope of 4% to 6% to maximize spring drainage. However, most of these maintenance solutions are aimed at dealing with conditions after they occur. This study was tasked with identifying alternative approaches in the literature to mitigate the problem. An annotated bibliographic record of literature on the topic of frost-heave and thaw-weakening of gravel roads was generated and organized by topic, and all documents were assessed in terms of a suitable rating for mitigating the problem in Iowa. Over 300 technical articles were collected and selected down to about 150 relevant articles for a full assessment. The documents collected have been organized in an electronic database, which can be used as a tool by practitioners to search for information regarding the various repair and mitigation solutions, measurement technologies, and experiences that have been documented by selected domestic and international researchers and practitioners. Out of the 150+ articles, 71 articles were ranked as highly applicable to conditions in Iowa. The primary mitigation methods identified in this study included chemical and mechanical stabilization; scarification, blending, and recompaction; removal and replacement; separation, and reinforcement; geogrids and cellular confinement; drainage control and capillary barriers, and use of alternative materials. It is recommended that demonstration research projects be established to examine a range of construction methods and materials for treating granular surfaced roadways to mitigate frost-heave and thaw-weakening problems. Preliminary frost-susceptibility test results from ASTM D5916 are included for a range of Iowa materials.

Interactive readings of children's literature in day care: Microgenetic analysis of the semiopictorial construction.

In line with educational issues involved in emergent literacy practices in preschool, in particular those concerning comprehension processes, this paper focuses on picture-based narrative comprehension during an interactive reading session of a wordless picture book, involving a group of children aged three and their teacher. Children are asked to make inferences about the meaning and outcome of the story, a procedure which gradually elicits their responses on how events link together, thus enhancing their capacity to use prior and implicit knowledge to build the story meaning. Moreover, this study highlights the importance of interaction for developing comprehension. Data collected was analysed following didactic microgenesis, an analytical approach showing that knowledge built during interaction depends on the joint construction of a zone of common meaning by which teacher and children try to adjust to each other. In order to help the process of merging different meanings of the story built online, a text written by researchers, following the narrative structure of the story, was read by the teacher after the picture-based reading. This led us to examine through interactional analysis which semiotic cues were used during recall on the following day, as an additional measure of knowledge construction.

Anterior subluxation after reduction of a posterior traumatic sterno-clavicular dislocation: a case report and a review of the literature.

Sternoclavicular dislocations represent a rare injury. Based on our clinical experience with a patient showing an anterior subluxation after reduction of a posterior traumatic dislocation, we review the literature. The emergent reduction of the dislocation is mandatory, always keeping in mind the potentially devastating neurovascular complications. If the treatment of a residual anterior instability remains controversial, a residual posterior instability should be treated by a surgical procedure. The optimal treatment depends mainly on each surgeon's choice and practice.

Two Cases of Interferon-Alpha-Induced Sarcoidosis Koebnerized along Venous Drainage Lines: New Pathogenic Insights and Review of the Literature of Interferon-Induced Sarcoidosis.

Sarcoidosis is a systemic granulomatous disorder of unknown origin commonly affecting the lung, the lymphoid system and the skin. We report here two cases of cutaneous sarcoidosis in two former intravenous drug users following interferon (IFN)-α and ribavirin therapy for chronic hepatitis C. Both patients developed skin sarcoidosis along venous drainage lines of both forearms, coinciding with the areas of prior drug injections. The unique distribution of the skin lesions suggests that tissue damage induced by repeated percutaneous drug injections represents a trigger for the local skin manifestation of sarcoidosis. Interestingly, skin damage was recently found to induce the local expression IFN-α, a well-known trigger of sarcoidosis in predisposed individuals. Here we review the literature on sarcoidosis elicited in the context of IFN-α therapy and propose a new link between the endogenous expression of IFN-α and the induction of disease manifestations in injured skin. © 2013 S. Karger AG, Basel.

Nonunion after fracture of the anterior tibial spine: case report and review of the literature.

Nonunion of anterior tibial spine of tibia in children is quite rare, but it could be associated with significant instability of the knee as it involves the fixation of anterior cruciate ligament. We report one case in which open reduction and internal fixation was carried out with good functional results. A literature review was performed to identify the cases reported of tibial eminence nonunion in children.

Urban Regeneration. A challenge for Public Art [1999]. Edition 2005

Urban Regeneration. A challenge for Public Art, supposed the start of a trend of critical thought related to the topics of Public Art, Urban Regeneration and Urban Design. This trend agglutinated around the Public Art Observatory that, still today, develops its activities.The book gathers a series of critical proposals organized in the chapters " Art and Design in/for Public Space ", " Forms and Representations of Public Art/Public Space. The Producer/User Dilemma " and " Public Art / Cities in Competition: Strategies, Bridges and Gateways ", with the participation of, among others, Sergi Valera, Ray Smith, Martí Peran, Ian Rawlinson, Chaké Matosian, Enric Pol, J. Hyatt, J. Gingell or T. Bovaird.

The Poetics and Politics of the American Gothic : Gender and Slavery in Nineteenth-Century American Literature

Taking as its point of departure recent insights about the performative¦nature of genre, The Poetics and Politics of the American Gothic¦challenges the critical tendency to accept at face value that gothic¦literature is mainly about fear. Instead, Agnieszka Soltysik Monnet¦argues that the American Gothic, and gothic literature in general,¦is also about judgment: how to judge and what happens when¦judgment is confronted with situations that defy its limits.¦Poe, Hawthorne, Melville, Gilman, and James all shared a concern¦with the political and ideological debates of their time, but tended¦to approach these debates indirectly. Thus, Monnet suggests, while¦slavery and race are not the explicit subject matter of antebellum¦works by Poe and Hawthorne, they nevertheless permeate it through¦suggestive analogies and tacit references. Similarly, Melville, Gilman,¦and James use the gothic to explore the categories of gender and¦sexuality that were being renegotiated during the latter half of the¦century. Focusing on The Fall of the House of Usher, The Marble¦Faun, Pierre, The Turn of the Screw, and The Yellow Wallpaper,¦Monnet brings to bear minor texts by the same authors that further¦enrich her innovative readings of these canonical works. At the same¦time, her study persuasively argues that the Gothic's endurance¦and ubiquity are in large part related to its being uniquely adapted¦to rehearse questions about judgment and justice that continue to¦fascinate and disturb.

Literature of pioneer life in Iowa, 1923

Contains history and a bibliography of books and pamphlets written about frontier and pioneer life in the midwest.