Gated Communities’ Contribution to the Urbanisation of Suburbia in Pilar, Argentina

Pilar is a city located in the third ring of the Buenos Aires metropolitan region (Argentina). Over the past 30 years, the widespread development of gated residential communities has seemingly gone hand-in-hand with an urbanisation of this outer suburb signalled by the arrival of new populations, enterprise, retail and other services. The growth of the ‘private city’ of these gated communities therefore has important implications for the ‘public city’ of the wider suburban municipality. Drawing upon original research based on the opinions of key informants, this paper considers how the growth of the ‘private city’ has contributed to the economy of, processes of community- building and social cohesion in Pilar. In conclusion, it is suggested that gated residential communities have been a major factor in the emergence of the dual suburb that is Pilar today

Framing the future: On local planning cultures and legacies

This paper considers the influence of established local planning cultures and legacies on the trajectory of contemporary local development policies. Local and sub-regional planning cultures are interpreted as overall 'developmental frames' which set the context for local planning approaches both through more concrete territorial, developmental and policy forms and through cognitive structures, assumptions and values. These frames then exert significant influence on how planning policy is conceived and enacted, with potentially major implications for local development outcomes. Three illustrative case studies are presented from sub-regional growth areas in the South East of England

Local and Global Deformation From Syncrotron Imaging of Closed Cell Foams in Compression

Foams are cellular structures, which are made from an increasingly wide variety of materials. Current foam processing methods randomly places cells, making a complex microstructure. These microstructures provide foams with the mechanical properties needed for excellent impact energy absorption as evidenced by their response under compressive stress. There are three primary regions of the stress-strain curve during compression: linear elastic, plateau, and densification. The combination of these three regions makes foams mechanically suitable for energy absorption. Recently, new metal foams made of Pd43Ni10Cu27P20 bulk metallic glass (BMG) have been successfully produced. Their mechanical properties were explored and an X-ray analysis procedure was developed. This procedure was also tested on a polymer (polymethacrylimide) foam with similar relative density to the metal foam. The polymer foam was tested in compression comparing two commercially available materials testers and a custom built Diffraction-Tomography Materials Tester (D-tmT) recently designed at OSU. Radiographs and tomographs were taken of the polymer sample while it was compressed using the D-tmT at the Advanced Photon Source. Control and sensing software was written in LabVIEW to automate tension, compression, and fatigue tests on the D-tmT. Similarly synchrotron radiation was used to monitor the microstructure of the BMG foam in compression. Dynamic compression was also performed for the first time on BMG foam using a Split Hopkinson Pressure Bar (SHPB). Image processing was used on the tomographs from both the polymer and BMG foams for qualitative comparison to computational results. Using advanced X-ray analysis, the mechanical properties of foams are understood through a connection with global stress and strain to local microstructure deformation.Mechanical & Aerospace Engineerin

A food web modeling assessment of Asian Carp impacts in the Middle and Upper Mississippi River, USA

The invasion of non-native fishes has caused a great detriment to many of our native fishes. Since the introduction of invasive carps, such as Silver, Bighead, Common and Grass Carp, managers and researcher have been struggling to remove these species while also hypothesizing the detriment of further invasion. This study developed a food web model of four locations on the Mississippi River and used those models to assess the impacts of two scenarios: carp removal and carp invasion. In the Middle Mississippi River where these invasive carps are already present, the models found that it would take a sustained exploitation of up to 30% of initial biomass over an extended period to remove Grass Carp and up to 90% removal of initial biomass to remove Silver and Bighead Carp. In the locations where Silver, Bighead, and Grass Carp are not yet established (i.e., Pools 4,8, and 13) the invasion of these species could cause declines from 10 to 30% in initial biomass of native fishes as well as already established nonnative invasive species

High porosity metallic glass foam: A powder metallurgy route

A powder metallurgy route to the fabrication of metallic glass foam is introduced. The method involves consolidating metallic glass powder blended with blowing agent particulates to produce expandable precursors, capable of yielding foams with porosities as high as 86%. The foams are found to inherit the strength of the parent metallic glass and to be able to deform heavily toward full densification absorbing high amounts of energy

Revisiting the multinational enterprise in global production networks

This paper presents further opportunities to develop the Global Production Network (GPN) approach by re-opening the ‘black box’ of the multinational enterprise (MNE) through a structuration perspective. It emphasises three aspects to a renewed focus on the agency of MNEs, namely: the importance of the variety of relationships within MNEs between parent and subsidiaries; the importance of dynamic capabilities in underpinning corporate change; and, the micro-politics of MNEs and subsidiaries which impact on firm-institutional change within regional economies. The agency exercised by MNEs in these ways influences the ‘selection’ of investment locations, ‘coupling’ processes, and the depth and pace of host territorial institutional change. In conclusion, this paper argues that future research needs to place greater emphasis on the contribution of dynamics internal to the MNE in order to understand evolution in regional economies and GPNs

Release of live baitfish by recreational anglers drives fish pathogen introduction risk

Emerging diseases of wildlife are an existential threat to biodiversity, and human-mediated movements of live animals are a primary vector of their spread. Wildlife disease risk analyses offer an appealing alternative to precautionary approaches because they allow for explicit quantification of uncertainties and consideration of tradeoffs. Such considerations become particularly important in high-frequency invasion pathways with hundreds of thousands of individual vectors, where even low pathogen prevalence can lead to substantial risk. The purpose of this study was to examine the landscape-level dynamics of human behavior-mediated pathogen introduction risk in the context of a high-frequency invasion pathway. One such pathway is the use and release of live fish used as bait by recreational anglers. We used a stochastic risk assessment model parameterized by angler survey data from Minnesota, USA, to simulate one year of fishing in Minnesota and estimate the total number of risky trips for each of three pathogens: viral hemorrhagic septicemia virus, the microsporidian parasite Ovipleistophora ovariae, and the Asian fish tapeworm Schizocotyle acheilognathi. We assessed the number of introductions under four scenarios: current/baseline conditions, outbreak conditions (increased pathogen prevalence), source-focused control measures (decreased pathogen prevalence), and angler-focused control measures (decreased rates of release). We found that hundreds of thousands of introduction events can occur per year, even for regulated pathogens at low pathogen prevalence. Reducing the rate of illegal baitfish release had significant impact on risky trips in scenarios where a high number of anglers were involved, but was less impactful in circumstances with limited outbreaks and fewer affected anglers. In contrast, reducing pathogen prevalence in the source populations of baitfish had relatively little impact. In order to make meaningful changes in pathogen introduction risk, managers should focus efforts on containing local outbreaks and reducing illegal baitfish release to reduce pathogen introduction risk. Our study also demonstrates the risk associated with high-frequency invasion pathways and the importance of incorporating human behaviors into wildlife disease models and risk assessments