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1.
This paper uses the resource curse hypothesis to explore diamond exploitation in Sierra Leone during the period 1930–2010. Focusing on national and local level analysis, it examines whether the net impact of diamond exploitation was a ‘resource curse’ or ‘blessing’ during four time periods: colonial and early post-independence era, the APC era, the civil war period, and post-war era. The paper argues that the net impact of diamond exploitation in Sierra Leone has not been constant; rather it has changed between resource blessing and curse over different major periods of Sierra Leone’s history and at local and national scales since inception of diamond exploitation. This paper illustrates that during the period 1968–1992 patrimonial politics undermined official diamond exploitation and significantly contributed to a pendulum shift in the net effects of diamond exploitation from resource blessing to curse. The study shows that the net effect of diamond exploitation was: a resource blessing (especially at the national level) prior to 1968; more of a resource curse during the APC era; a full blown manifestation of the curse during the civil war period; and that governance of the diamond sector has improved sufficiently in post-civil war Sierra Leone to start the gradual transformation of diamonds to resource blessing, at national and local levels.  相似文献   

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Water samples were collected from the Truckee River-Pyramid Lake system, the Walker River-Walker Lake system, and the Carson River, all located in eastern California and western Nevada, U.S.A., at three different times (i.e., summer 1991, spring 1992, and autumn 1992) over a two year period. The concentrations of As, Na, Cl, PO4, and pH were measured in these river samples and the associated terminal lakes. Arsenic values ranged from below 13 nmol/kg near Truckee, California to 160 nmol/kg at Nixon, Nevada in the Truckee River, from 40 nmol/kg in the headwaters of both West and East Walker Rivers to 270 nmol/kg below Weber Reservoir on the main branch of the Walker River, and from <27 nmol/kg to 234 nmol/kg for the lower Carson River system. Arsenic concentrations in Steamboat Creek (0.91 mol/kg–1.80 mol/kg) in the Truckee River catchment are above the U.S. EPA drinking water maximum contaminant level of 0.67 mol/kg, as are the As concentrations in both Pyramid Lake (1.33 mol/kg–1.57 mol/kg ) and Walker Lake (13.7 mol/kg–18.7 mol/kg). Sources of As for all three rivers include weathering of As-rich rocks and/or regolith and input of high-As geothermal spring waters, both processes primarily, although not exclusively, adding As to the headwater regions of these rivers. Steamboat Hot Springs (29 mol/kg As 54.5 mol/kg), for example, is identified as a source of As to the Truckee River via Steamboat Creek. The high As concentrations in Pyramid and Walker Lakes are likely due to (1) desorption of arsenate from aquatic particulate matter in these high pH waters (9.0 pH 9.5), (2) limited biologic uptake of arsenate, and (3) evaporative concentration of the lake waters. Evaluation of molar PO4}/As ratios of river waters and geothermal spring waters (e.g., Steamboat Hot Springs), indicates that phosphate is substantially enriched in Steamboat Creek as well as the mid to lower reaches of the Walker and Carson Rivers. These regions of each river are dominated by agricultural interests and, additionally, in the case of Steamboat Creek, residential areas and golf courses. Our data strongly imply that phosphate-rich agricultural return flow has likely added P to these streams and, consequently, increased their respective P:As ratios.  相似文献   

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Urs Geiser 《Geoforum》2012,43(4):707-715
In recent years, the Swat valley in North-West Pakistan has witnessed various waves of ‘politics’. Different groups have attempted to change socio-economic conditions, each according to their clear visions of a better future. After a period of top-down attempts at modernisation by the state, development projects inspired by deliberative democracy have attempted to increase political space for ‘local people’, but failed. Swat has also witnessed agonistic politics, with the emergence of a fundamentalist social movement that constructed a radical discourse of otherisation, entering into an antagonism with the state that created war and havoc. Thus, Swat offers a challenging learning ground to reflect on practices for producing change, as well as on theoretical currents in academia. I argue that deliberative and radical theorising provide insights into the political life of Swat, but fall short analytically (missing social complexities), procedurally (favouring specific techniques of social negotiation), and normatively (due to preconceived understandings of a ‘better future’). I substantiate my argument by showing that both positions take euro-centric conceptualisation of ‘citizens’, a (modern) ‘state’, and ‘citizen/state relations’ as universals – basic conditions that are not met in the post-colonial setting of Swat. I therefore argue that our curiosity should be redirected from ontologised explanation to an analysis of actual practices of societal negotiation and the norms within which these are embedded. Such insights will make it possible for us to appreciate the enormous challenges people in Swat face in their struggle to negotiate aspirations among disparate voices and to imagine some common understanding of a ‘better future’ – challenges that go beyond what deliberative or agonistic theorising can offer.  相似文献   

5.
Clare Herrick 《Geoforum》2012,43(6):1045-1056
While attention to the socio-ecological and political economic influences on health grows, there remains a paucity of political ecological analyses of health (King, 2010). At the same time, the growing burden of non-communicable diseases (NCDs) in the Global South demands new conceptual and pragmatic engagements with their modifiable risk factors. Drawing on the example of South Africa, this paper argues that alcohol consumption might usefully be theorised in political ecological lexicon as a “disaster”. To do so, it draws attention to the upstream causes of vulnerability, rather than just the downstream effects of risky drinking. This reorientation is needed for sustainable, publicly acceptable alcohol policies. To realise this, it draws on Blaikie et al.’s (1994, 2003) political ecological approach to risk, vulnerability and coping and, more specifically, applies their Pressure and Release model to explore liquor as a situated “disaster” in South Africa’s Western Cape province. In so doing, it aims to mark out an under-explored research agenda that considers alcohol as a pervasive governance dilemma. In addition, it also reflects on the model’s utility as a means of communicating findings that might reorient policy discussions on alcohol control in both South Africa and countries of the Global South.  相似文献   

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This paper investigates the kinetics of biogenic silica dissolution in seawater, through batch dissolution, where the reaction is observed as the increase in dissolved silicic acid concentration with time. It utilises new data from dissolution of the marine diatom Cyclotella cryptica, and the freshwater diatom C. meneghiniana, as well as literature results. The sum of exponentials form: , is hypothesised as the most general rate equation, with the single exponential form occurring in a minority of cases. The consistency of this behaviour with a near-exponential decay of surface area with time, an appropriate mathematical integration, and surface heterogeneity, is discussed. (Serious errors in some existing integrations are identified.) The rate of dissolution at constant surface area is shown to decrease non-linearly as the ambient concentration of silicic acid increases. A fractional order with respect to silicic acid in the back reaction, close to 0.5, leads to a mechanism in which an intermediate is formed from the surface and an, as yet, unidentified molecule, probably water. Good preliminary fits are found between the model and literature results found using entirely different methods. A parallel treatment of hydrogen ion dependency is suggested. The likely distortion of full reaction curves from exponential behaviour imposed by the back reaction, is considered in detail.  相似文献   

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Altered variolites described for the first time in the axial zone of the Mid-Atlantic Ridge are represented by rounded globules of andesite (icelandite) composition with light trachyandesite rim embedded in a picrobasaltic matrix. The globules were transferred with picrobasaltic melt and then floated to the surface of lava flow, while formation of leucocratic rims was presumably related to thermodiffusion (Soret effect) in a cooling heterogeneous melt. This heterogeneous melt was formed by penetration of ascending column of picrobasaltic magma in already existing small intracructsal magmatic chamber filled with residual icelanditetype andesite melt and involvement of the latter into a general upward movement. The rapid ascent of the melts in the oceanic spreading zones by means of turbulent flowing caused dispersion of the extragenous melt into small drops in a jet of picrobasaltic magma, without their interaction. Variolites were formed during cooling of such heterogeneous lava flow. No signs of liquid immiscibility were found in the studied variolites.  相似文献   

8.
Water samples were collected from 10 locations along the Truckee River system, 14 locations along the Walker River system, and 12 locations along the Carson River, and analyzed for B, Mo, V, W, Na, Cl, and pH. Boron concentrations ranged from approximately 2 mol/kg in the upper reaches of the Truckee River to almost 1,200 mol/kg in Pyramid Lake. Molybdenum, V, and W had concentrations in the nanomolal range; Mo varied from a low of about 12 nmol/kg to a high of 3,200 nmol/kg (Walker Lake); V ranged from 9 nmol/kg to approximately 470 nmol/kg; and W varied from a low value around 0.8 nmol/kg (West Walker River) to 1,030 nmol/kg. The high concentrations of these oxyanion-forming trace elements in the rivers reflects (1) the relative stability of these oxyanions (e.g., MoO4 2-, HVO4 2-, WO4 2-, B(OH)3, and/or B(OH)4 -) in the alkaline, well oxygenated river and lake waters, (2) contributions of hydrothermal waters (especially for B), and (3) weathering of rocks/regolith with high concentrations of these elements. In the case of Mo, V, and W, each exhibited relatively conservative behavior in the upper, oxygenated reaches of all three rivers. During the study period the region experienced a prolonged drought such that the lower reaches of each river were typified by no flow or stagnant waters and probably low oxygen and/or anoxic conditions (although not measured). Reductive processes occurring in the low flow to stagnant reaches of each river could have led to removal of Mo, V, and W from solution as coprecipitates with Fe monosulfides, or via sorption to Fe oxides/oxyhydroxides and/or organic matter. Boron, however, exhibited essentially no or minor removal from these rivers, and instead was added to each river via B-rich hydrothermal waters (e.g., Steamboat Creek from Steamboat Hot Springs), or by B-rich groundwaters via base-flow during the extensive drought.  相似文献   

9.
Evidence of Cenozoic magmatism is found along the length of New Guinea. However, the petrogenetic and tectonic setting for this magmatism is poorly understood. This study presents new field, petrographic, U–Pb zircon, and geochemical data from NW New Guinea. These data have been used to identify six units of Cenozoic igneous rocks which record episodes of magmatism during the Oligocene, Miocene, and Pliocene. These episodes occurred in response to the ongoing interaction between the Australian and Philippine Sea plates. During the Eocene, the Australian Plate began to obliquely subduct beneath the Philippine Sea Plate forming the Philippine–Caroline Arc. Magmatism in this arc is recorded in the Dore, Mandi, and Arfak volcanics of NW New Guinea where calc-alkaline and tholeiitic rocks formed within subduction-related fore-arc and extension-related back-arc settings from 32 to 27 Ma. Collision along this plate boundary in the Oligocene–Miocene jammed the subduction zone and caused a reversal in subduction polarity from north-dipping to south-dipping. Following this, subduction of the Philippine Sea Plate beneath the Australian Plate produced magmatism throughout western New Guinea. In NW New Guinea this is recorded by the middle Miocene (18–12 Ma) Moon Volcanics, which include an early period of high-K to shoshonitic igneous activity. These earlier magmatic rocks are associated with the subduction zone polarity reversal and an initially steeply dipping slab. The magmatic products later changed to more calc-alkaline compositions and were emplaced as volcanic rocks in the fore-arc section of a primitive continental arc. Finally, following terminal arc–continent collision in the late Miocene–Pliocene, mantle derived magmas (including the Berangan Andesite) migrated up large strike-slip faults becoming crustally contaminated prior to their eruption during the Plio–Pleistocene. This study of the Cenozoic magmatic history of NW New Guinea provides new data and insights into the tectonic evolution of the northern margin of the Australian Plate.  相似文献   

10.
The diverse residents of the urban global South experience insecurities in everyday, immediate and subjective ways. Lemanski argues these insecurities relate not only to physical concerns like fear, crime, and violence but also to stressors like insecure tenure and financial situations, and threatened and contested lifestyles and cultures as cities rapidly change. This paper considers how diverse ‘everyday human (in)securities’ manifest through urban nature and shape collaborations around nature conservation. The focus is on protected coastal dunes in Cape Town and collaborative conservation participants, including municipal nature conservators and community representatives from the adjacent apartheid-era ‘townships’. The diverse ‘everyday human (in)securities’ perceived and experienced by these participants manifest variously in physical threats to bodies and biodiversity, but also in relation to the insecure tenure and financial situations experienced by residents and conservators alike, alongside differing cultural values of nature. Through attention to diffuse power relations and everyday experiences, divergent perceptions of (in)security are shown to be frictional and sometimes paradoxical in nature. Yet identifying these (in)securities also holds potential for exploring hopeful and productive negotiations around what ‘security’ might mean, and how it might be realised through the collaborations – bringing into dialogue contested spaces of urban nature in cities of the global South and North.  相似文献   

11.
By focusing on Kunshan, an economically advanced county-level city in the Yangtze River Delta, this paper aims to answer how, why, and under what circumstances the territorial power of Chinese urban entrepreneurial states is created in response to the dynamics of spatial economic development in the context of market transition and globalization. Although Kunshan is merely a county-level authority administratively, its economic performance in 2011 was better than that of several poor provinces, such as Hainan, Tibet, Qinghai, and Ningxia. Kunshan’s successful urban entrepreneurialism presents a unique ‘mismatch’ between ‘low’ administrative rank and ‘great’ economic performance (a big foot in a small shoe, dajiao chuan xiaoxie). I argue that Kunshan has developed several new local state powers through flexible administrative restructuring that explains the ‘mismatch’ puzzle and includes the following characteristics: (1) reclassification of Kunshan from county to county-level city, (2) relational adjustment by officially or informally raising Kunshan’s place rank and the cadre rank, and (3) boundary revision by virtual enclave enlargement. I conclude that the Chinese party-state system plays a role in Chinese county-level urban entrepreneurialism.  相似文献   

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In order to evaluate the extent of CO2–water–rock interactions in geological formations for C sequestration, three batch experiments were conducted on alkali feldspars–CO2–brine interactions at 150–200 °C and 300 bars. The elevated temperatures were necessary to accelerate the reactions to facilitate attainable laboratory measurements. Temporal evolution of fluid chemistry was monitored by major element analysis of in situ fluid samples. SEM, TEM and XRD analysis of reaction products showed extensive dissolution features (etch pits, channels, kinks and steps) on feldspars and precipitation of secondary minerals (boehmite, kaolinite, muscovite and paragonite) on feldspar surfaces. Therefore, these experiments have generated both solution chemistry and secondary mineral identity. The experimental results show that partial equilibrium was not attained between secondary minerals and aqueous solutions for the feldspar hydrolysis batch systems. Evidence came from both solution chemistry (supersaturation of the secondary minerals during the entire experimental duration) and metastable co-existence of secondary minerals. The slow precipitation of secondary minerals results in a negative feedback in the dissolution–precipitation loop, reducing the overall feldspar dissolution rates by orders of magnitude. Furthermore, the experimental data indicate the form of rate laws greatly influence the steady state rates under which feldspar dissolution took place. Negligence of both the mitigating effects of secondary mineral precipitation and the sigmoidal shape of rate–ΔGr relationship can overestimate the extent of feldspar dissolution during CO2 storage. Finally, the literature on feldspar dissolution in CO2-charged systems has been reviewed. The data available are insufficient and new experiments are urgently needed to establish a database on feldspar dissolution mechanism, rates and rate laws, as well as secondary mineral information at CO2 storage conditions.  相似文献   

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