Sediment geochronology and spatio-temporal and vertical distributions of radionuclides in the Upper Bonny Estuary (South Nigeria)

Surface deposits and sediment cores were collected from the Upper Bonny Estuary, located in Southwest Nigeria, and analyzed to determine spatio-temporal and vertical distributions of radio-nuclide activities expressed in Bq·kg^?1 dry weight. The results of activities of naturally occurring radionuclides of ²²⁶Ra (15 ± 2–34 ± 3 Bq·kg^?1), ²²⁸Ra (32 ± 5–48 ± 6 Bq·kg^?1), ⁴⁰K (264 ± 29–462 ± 36 Bq·kg^?1) were found to be all within the range of typical values reported for coastal regions. Ratios of ²²⁶Ra to ²²⁸Ra suggested accretion for all samples with low sediment accumulation registered during rainy months. In addition, vertical distributions at the three sampling sites were also studied with the initial aim of establishing chronologies from the decay of excess ²¹⁰Pb. In two cores, excess ²¹⁰Pb, estimated by subtracting ²²⁶Ra from total ²¹⁰Pb on a layer-by-layer basis, exhibit relatively constant activity with discrete minima and maxima. Therefore, these cores were excluded from radiometric dating. Only the third core could be dated by the constant rate of supply model, and ¹³⁷Cs was utilized to validate the ²¹⁰Pb chronology.     

Tocqueville on Pantheism,Materialism, and Catholicism

Abstract

It is widely acknowledged that Leo Strauss was an extraordinary scholar and teacher who strove to open up forgotten vistas of philosophical inquiry. Gigantic controversy rages, however, about the sorts of political and social changes, if any, that he hoped to promote. The fire has been fueled by the alleged contributions of Straussians to the Iraq War—and by the publication of Strauss's 1933 letter that commended “fascist, authoritarian, and imperial” principles. This article reviews and then updates the assessments proffered in my 2009 book (Straussophobia) about the state of the “Strauss Wars.” Critics such as Shadia Drury continue to embarrass themselves in prestigious venues, but newer voices are using innovative strategies to argue that Strauss was attempting to undermine the principles of American democracy. Whereas William Altman relies on “esoteric interpretations” of Strauss's writings, Alan Gilbert illuminates Strauss's behind-the-scenes efforts regarding policy disputes. Although I maintain that Gilbert and especially Altman have made invaluable contributions, I argue that they both overreach.     

A geographer in heritage. Responding to ‘decennial reflections’

This article is a comment on: Tubridge et al., 2012. Decennial reflections on a ‘geography of heritage’ (2000). International Journal of Heritage Studies, DOI: 10.1080/13527258.2012.695038     

Quantification of Linked Column Frame Seismic Performance Factors for Use in Seismic Design

Previous research has proposed the Linked Column Frame (LCF) as a lateral load-resisting system capable of providing rapid return to occupancy for buildings impacted by moderate earthquake events and collapse prevention in very large events. The LCF consists of flexible moment frames (MF) and linked columns (LC), which are closely spaced dual columns interconnected with bolted links. The linked columns (LC) are designed to limit seismic forces and provide energy dissipation through yielding of the links, while preventing damage to the moment frame under certain earthquake hazard levels. The proposed design procedure ensures the links of the linked column yield at a significantly lower story drift than the beams of the moment frame, enabling design of this system for two distinct performance states: rapid repair, where only link damage occurs and quick link replacement is possible; and collapse prevention, where both the linked column and moment frame may be damaged.

Here, the seismic performance factors for the LCF system, including the response modification factor, R, the system over-strength factor, Ω₀, and the deflection amplification factor, C_d, are established following the procedures described in FEMA P695 [2009]. These parameters are necessary for inclusion of the system in the building code. This work describes the development of archetype structures, numerical models of the LCF systems, incremental dynamic analyses, and interpretation of the results. From the results, it is recommended that R, Ω₀, and C_d values of 8, 3, and 5.5 be used for seismic design of the LCF system. A height limit of 35 m (115ft) is recommended at this time as taller LCFs are not considered in this study.     

Writing Political Forests

In this essay, we highlight the intellectual context that shaped our initial conceptualisation of political forests as dynamic spaces and political ecologies, and how our fieldwork and comparative approach shaped our subsequent elaboration of the concept and its empirical manifestations. Of particular significance was our emphasis on incorporated/relational comparison and our multiscale analysis. These approaches allowed us to locate subjects and processes in specific field sites within an emergent global forestry network produced through multiscale interactions and movements within and among colonial and FAO forestry empires. We revisit the key processes through which we learned to see common and contrasting mechanisms that have made forests inherently political in our six research sites in Indonesia, Malaysia, and Thailand, linking these “classic” mechanisms to concepts in wide use today. These concepts include understanding political forests as co-produced, the significance of expertise in their reproduction, and the interactions between politics and the lively materialities of political forests. Among other conclusions, we suggest that the political forest is being replaced by what could be called “political conservation”, which has its own knowledge networks and expertise that displace but also build on political forestry. Finally, we reflect on how these ideas are being further developed by the authors in this symposium, whom we gratefully acknowledge for demonstrating that the politicisation of forests continues to be significant today.     

Citizen and government co-production of data: Analyzing the challenges to government adoption of VGI

With the recent rise of open government and open data initiatives, governments are increasingly adopting new approaches of citizen participation to support a more democratic, transparent, and inclusive government system. Among other forms of citizen participation, Volunteered Geographic Information (VGI) is one approach to connecting citizens and government. Accepting VGI as a way to update government data or collect near-real-time information from citizens can create a partner-like relationship where citizens voluntarily contribute time and effort to support government actions. However, as a relatively new approach to citizen participation and data collection, VGI requires evaluation from the perspective of governments. This research investigates the challenges and opportunities that governments have found through the implementation of VGI projects. Results are drawn from interviews conducted with 19 government organizations, revealing organizational and technical challenges that limit the adoption of VGI. Organizational challenges are associated with government mindset, implementation, and project management, while technical challenges involve development of the system and quality of data. Given these challenges, we derive recommendations within the phases of project initiation, implementation, and expansion that can foster VGI adoption in government.