The social production of ecosystem services: A framework for studying environmental justice and ecological complexity in urbanized landscapes

AbstractA framework is constructed for how to relate ecosystem services to environmental justice. The benefits humans and society can derive from biophysical processes cannot be viewed as objectively existing “out there”, but as entangled in social and political processes. This is unpacked through the analytical moments of generation, distribution and articulation of ecosystem services. Social practice moderates the generation of benefits from biophysical processes (through urban development patterns and day-to-day management of urban ecosystems), but also who in society that benefits from them, i.e. the distribution of ecosystem services (viewed here as the temporal and spatial scales at which it is possible for humans to benefit from biophysical processes). Moreover, for biophysical processes to attain value in decision-making, a social practice of value articulation is needed. The framework then moves between two levels of analysis. At the city-wide level, an ecological network translates how urban ‘green’ areas, viewed as nodes, are interconnected by ecological flows (water, species movement, etc.) where nodes have different protective and management capacities. The network captures spatial complexity—what happens in one location, can have effects elsewhere. At the local level, urban struggles over land-use are studied to trace how actors utilize artifacts and social arenas to articulate how certain biophysical processes are of value. Competing networks of value articulation strive to influence land-use, and multiple local studies bring understanding of how power operates locally, informing city-wide analyses. Empirical studies from Stockholm, Cape Town and other cities inform the framework

Alien Registration- Ernstson, Louise (Bradford, Penobscot County)

https://digitalmaine.com/alien_docs/10274/thumbnail.jp

Alien Registration- Ernstson, Charles (Bradford, Penobscot County)

https://digitalmaine.com/alien_docs/10273/thumbnail.jp

Las estructuras de impacto doble del terciario medio de Azuara y Rubielos de la Cérida (España)

We report on the Azuara impact structure and its Rubielos de la Cérida companion crater, which establish the largest terrestrial doublet impact structure presently known. Both structures have diameters of roughly 35 – 40 km and they have been formed in a purely sedimentary target. From stratigraphic considerations and palaeontologic dating, an Upper Eocene or Oligocene age is very probable Geological mapping has established abundant geologic impact evidence in the form of monomictic and polymictic breccias and breccia dikes, megabreccias, dislocated megablocks, remarkable structural features, extensive impact ejecta and impact signatures even in distant autochthonous deposits. The most striking impact evidence for both structures is given by strong shock metamorphism, including melt and diaplectic glass, planar deformation features (PDFs), different kinds of impact melt rocks (from former silicate melt, carbonate melt, carbonate-phosphate melt) and suevite breccias. Glassy amorphous carbon particles in a solid C-O compound may be related with fullerenes and may originate from a quenched melt of extremely shocked coal or from extremely shocked limestones. It is assumed that the impact had considerable influence on the Mid-Tertiary regional geology of the Iberian System, and we suggest that respective geologic models which have so far not considered this peculiar and far-reaching event, need considerable revision. Key words: Azuara impact structure, Rubielos de la Cérida impact structure, Iberian chain (Spain), shock metamorphism, impact melt rocks, impact breccias, ejecta, Tertiary.El presente artículo se centra en las estructuras de impacto de Azuara y Rubielos de la Cérida, que con diámetros de aproximadamente 35-40 Km fueron generadas en un objetivo puramente sedimentario. Ambas constituyen la estructura terrestre de impacto doble de mayor tamaño conocida hasta el momento. A partir de los datos estratigráficos y paleontológicos, su edad más probable es Eoceno sup. u Oligoceno. La cartografia geológica realizada ha permitido localizar abundantes evidencias de impacto e incluso efectos del impacto en depósitos autóctonos distantes. La evidencia de impacto más importante para ambas estructuras viene dada por la presencia de un intenso metamorfismo de choque, incluyendo fundido y vidrio diapléctico, rasgos de deformación planar (PDFs), diferentes tipos de rocas de fundido de impacto (formadas a partir de fundido silicatado, de fundido carbonatado y fundido de carbonato-fosfato) y brechas suevíticas. Partículas de vidrio carbonoso amorfo sitas en un componente sólido de C-O pueden estar relacionadas con fullerenos, y haberse formado a partir del enfriamiento de un fundido procedente o bien de carbón intensamente chocado o bien de calizas intensamente chocadas. Pensamos que el impacto tuvo una influencia considerable en el terciario medio de esta región del Sistema Ibérico, y sugerimos que aquellos modelos en los que no se ha tenido en cuenta este evento peculiar y de amplia repercusión necesitan una revisión considerable. Palabras clave: Estructura de impacto de Azuara, estructura de impacto de rubielos de la Cérida, Cadena Ibérica (España), metamorfismo de choque, rocas de fundido de impacto, brechas de impacto, eyecta, Terciario

Conceptual vectors of African urbanism : 'engaged theory-making' and 'platforms of engagement'

ERNSTSON H., LAWHON M. and DUMINY J. Conceptual vectors of African urbanism: ‘engaged theory-making’ and ‘platforms of engagement’, Regional Studies. With increasing urbanization in the global South, and Africa in particular, scholars have called attention to the limited explanatory capacity of existing theory. Ananya Roy suggests developing conceptual vectors based on regional histories and contexts. Two such vectors with relevance beyond Africa are identified and developed in this paper. The developmentalist focus of African urban work provides insights into challenges of linking academic theory with progressive changes in practice, what is called here ‘engaged theory-making’; and conditions of informality enable ‘platforms of engagement’ – particular modes of organizing towards radical incremental change. The strengths of African research are highlighted, critical questions are raised and further work is encouraged.ERNSTSON H., LAWHON M. et DUMINY J. Des vecteurs conceptuels de l’urbanisme africain: la ‘construction des théories engagées’ et des ‘plates-formes d’engagement’, Regional Studies. Face à l’urbanisation accrue dans le monde méridionale, et en Afrique en particulier, les savants ont attiré l’attention à la capacité explicative limitée de la théorie actuelle. Ananya Roy suggère la construction de vecteurs conceptuels fondés sur des histoires et des contextes régionaux. Cet article cherche à identifier et à développer deux de ces vecteurs dont la pertinence va au-delà de l’Afrique. L’accent développementaliste mis sur le travail urbain à propos de l’Afrique donne des aperçus du défi de lier la théorie savante aux changements progressifs des pratiques, ce que l’on appelle ici la ‘construction des théories engagées’; et les conditions de simplicité permettent des ‘plates-formes d’engagement’ – des modes d’organisation particuliers sur la voie des changements successifs radicaux. On souligne les points forts de la recherche africaine, il se pose des questions fondamentales et on encourage un approfondissement de la recherche.ERNSTSON H., LAWHON M. and DUMINY J.非洲城市主义的概念向量：‘参与的理论建构’与‘参与平台’，区域研究。随着 全球南方的日益城市化，特别是非洲地区，学者们已开始呼吁关注既有理论解释能力的局限性。罗伊（Ananya Roy） 建议根据区域的历史及脉络来发展概念向量，本文便将指认并建构此般超越非洲关联性的两个向量。发展主义对于非 洲城市的关注，为连结学术理论与实际的激进变革之挑战提供了洞见，在此称之为‘参与的理论建构’；而非正式性的 状态，则使得‘参与的平台’—亦即有助于达成激进且递增的变革的特别组织模式—成为可能。本文将凸显非洲研究的 长处，提出批判性的问题，并促进未来的研究工作。Swedish Research Council Formas which provided public funding through the research grant Ways of Knowing Urban Ecologies (WOK-UE) [grant number 250-2010-1372]http://www.regionalstudies.orghb201

Towards a Comparative Understanding of Community-led and Collaborative Responses to Covid-19 in Kampala, Mogadishu and Nairobi

In this paper, we explore the Covid-19 pandemic’s evolving impacts and wide-ranging local initiatives in Mogadishu, Kampala, and Nairobi. Low-income residents often experienced Covid-19 less as a health crisis (especially in its early waves) and more in terms of its devastating socioeconomic, political and violent impacts. Although there were widespread misconceptions about the virus and vaccine, private sector and civil society groups also raised awareness about Covid-19 via several creative initiatives that can usefully complement official risk communication strategies. Moreover, we found a range of Covid-19 responses at different scales, including national taskforces; philanthropic and private sector initiatives; aid agency initiatives; and grassroots and other civil society interventions. Some new collaborations and constructive engagements emerged between state and non-state groups. An array of non-state actors – including community health volunteers (CHVs), private firms, youth, women’s, faith-based and refugee-led organisations – were key in assisting marginalised residents, but these efforts would benefit considerably from additional government support and recognition. We develop a typology of responses that ranges from quite top-down coalitions to increasingly bottom-up community solidarity networks. The typology encompasses efforts around emergency relief distribution, risk communication, service delivery, livelihoods strengthening and data collection. Collaborations between state and non-state actors took various forms but were typically emergency responses, which did not necessarily adopt a strategic, longer term approach to addressing urban poverty and deprivation. Other interventions – such as enhancing health systems, countering police brutality, supporting multi-sectoral upgrading and engaging constructively with informality – may open newfound possibilities of more lasting, equitable change

Thinking through heterogeneous infrastructure configurations

Studies of infrastructure have demonstrated broad differences between Northern and Southern cities, and deconstructed urban theory derived from experiences of the networked urban regions of the Global North. This includes critiques of the universalisation of the historically–culturally produced normative ideal of universal, uniform infrastructure. In this commentary, we first introduce the notion of ‘heterogeneous infrastructure configurations’ (HICs) which resonates with existing scholarship on Southern urbanism. Second, we argue that thinking through HICs helps us to move beyond technological and performative accounts of actually existing infrastructures to provide an analytical lens through which to compare different configurations. Our approach enables a clearer analysis of infrastructural artefacts not as individual objects but as parts of geographically spread socio-technological configurations: configurations which might involve many different kinds of technologies, relations, capacities and operations, entailing different risks and power relationships. We use examples from ongoing research on sanitation and waste in Kampala, Uganda – a city in which service delivery is characterised by multiplicity, overlap, disruption and inequality – to demonstrate the kinds of research questions that emerge when thinking through the notion of HICs

Streaming potential measurements 1. Properties of the electrical double layer from crushed rock samples

The ξ potential has been inferred from streaming potential measurements with crushed rock samples as a function of pH and electrolyte concentration for various salts. The value obtained for crushed Fontainebleau sandstone at pH = 5.7 and a KCl solution with a resistivity of 400 Ω m is −40 ± 5 mV, where the error is dominated by sample to sample variations. The sensitivity of the ξ potential to the electrolyte resistivity for KCl is given experimentally by ρ_f^(0.23±0.014) where ρ_f is the electrolyte resistivity. The point of zero charge (pzc) is observed for pH = 2.5 ± 0.1, and the ξ potential is positive for pH pzc. For pH > 5 the variations of the ξ potential with pH can be approximated by ξ(pH)/ξ(5.7) = 1 + (0.068 ± 0.004)(pH - 5.7) for ρ_f = 100 Ω m. The ξ potential has been observed to be sensitive to the valence of the ions and is approximately reduced by the charge of the cation, unless specific adsorption takes place like in the case of Al^3+. The experimental results are well accounted for by a three-layer numerical model of the electrical double layer, and the parameters of this model can be evaluated from the experimental data. The sensitivity of the ξ potential to the rock minerals has also been studied. The ξ potential obtained for granitic rocks is comparable to that obtained for Fontainebleau sandstone but can be reduced by a factor of 2–4 for sandstones containing significant fractions of carbonates or clay. To take into account the effect of the chemical composition of the electrolyte, a chemical efficiency is defined as the ratio of the ξ potential to the ξ potential measured for KCl. This chemical efficiency is measured to be ∼80% for typical groundwater but can be as low as 40% for a water with a high dissolved carbonate content. The set of empirical laws derived from our measurements can be used to assess the magnitude of the streaming potentials expected in natural geophysical systems

Mid-sized complex crater formation in mixed crystalline-sedimentary targets: Insight from modeling and observation

Large impact crater formation is an important geologic process that is not fully understood. The current paradigm for impact crater formation is based on models and observations of impacts in homogeneous targets. Real targets are rarely uniform; for example, the majority of Earths surface is covered by sedimentary rocks and/or a water layer. The ubiquity of layering across solar system bodies makes it important to understand the effect target properties have on the cratering process. To advance understanding of the mechanics of crater collapse, and the effect of variations in target properties on crater formation, the first Bridging the Gap workshop recommended that geological observation and numerical modeling focussed on mid-sized (15-30 km diameter) craters on Earth. These are large enough to be complex; small enough to be mapped, surveyed and modelled at high resolution; and numerous enough for the effects of target properties to be potentially disentangled from the effects of other variables. In this paper, we compare observations and numerical models of three 18-26 km diameter craters formed in different target lithology: Ries, Germany; Haughton, Canada; and El'gygytgyn, Russia. Based on the first-order assumption that the impact energy was the same in all three impacts we performed numerical simulations of each crater to construct a simple quantitative model for mid-sized complex crater formation in a subaerial, mixed crystalline-sedimentary target. We compared our results with interpreted geological profiles of Ries and Haughton, based on detailed new and published geological mapping and published geophysical surveys. Our combined observational and numerical modeling work suggests that the major structural differences between each crater can be explained by the difference in thickness of the pre-impact sedimentary cover in each case. We conclude that the presence of an inner ring at Ries, and not at Haughton, is because basement rocks that are stronger than the overlying sediments are sufficiently close to the surface that they are uplifted and overturned during excavation and remain as an uplifted ring after modification and post-impact erosion. For constant impact energy, transient and final crater diameters increase with increasing sediment thickness.The Meteoritics & Planetary Science archives are made available by the Meteoritical Society and the University of Arizona Libraries. Contact [email protected] for further information.Migrated from OJS platform February 202