911 resultados para potential land productivity


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There is a growing interest in the use of geophysical methods to aid investigation and monitoring of complex biogeochemical environments, for example delineation of contaminants and microbial activity related to land contamination. We combined geophysical monitoring with chemical and microbiological analysis to create a conceptual biogeochemical model of processes around a contaminant plume within a manufactured gas plant site. Self-potential, induced polarization and electrical resistivity techniques were used to monitor the plume. We propose that an exceptionally strong (>800 mV peak to peak) dipolar SP anomaly represents a microbial fuel cell operating in the subsurface. The electromagnetic and electrical geophysical data delineated a shallow aerobic perched water body containing conductive gasworks waste which acts as the abiotic cathode of microbial fuel cell. This is separated from the plume below by a thin clay layer across the site. Microbiological evidence suggests that degradation of organic contaminants in the plume is dominated by the presence of ammonium and its subsequent degradation. We propose that the degradation of contaminants by microbial communities at the edge of the plume provides a source of electrons and acts as the anode of the fuel cell. We hypothesize that ions and electrons are transferred through the clay layer that was punctured during the trial pitting phase of the investigation. This is inferred to act as an electronic conductor connecting the biologically mediated anode to the abiotic cathode. Integrated electrical geophysical techniques appear well suited to act as rapid, low cost sustainable tools to monitor biodegradation.

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THE MACHINIST LANDSCAPE: AN ENTROPIC GRID OF VARIANCE
‘By drawing a diagram, a ground plan of a house, a street plan to the location of a site, or a topographic map, one draws a “logical two dimensional picture”. A “logical picture” differs from a natural or realistic picture in that it rarely looks like the thing it stands for.’
A Provisional Theory of Non-Sites, Robert Smithson (1968)

Between design and ground there are variances, deviations and gaps. These exist as physical interstices between what is conceptualised and what is realised; and they reveal moments in the design process that resist the reconciliation of people and their environment (McHarg 1963). The Machinist Landscape interrogates the significance of these variances through the contrasting processes of coppice and photovoltaic energy. It builds on the potential of these gaps, and in doing so proposes that these spaces of variance can reveal the complexity of relationships between consumption and remediation, design and nature.
Fresh Kills Park, and in particular the draft master plan (2006), offers a framework to explore this artificial construct. Central to the Machinist Landscape is the analysis of the landfill gas collection system, planned on a notional 200ft grid. Variations are revealed between this diagrammatic grid measure and that which has been constructed on the site. These variances between the abstract and the real offer the Machinist Landscape a powerful space of enquiry. Are these gaps a result of unexpected conditions below ground, topographic nuances or natural phenomena? Does this space of difference, between what is planned and what is constructed, have the potential to redefine the dynamic processes and relations with the land?
The Machinist Landscape is structured through this space of variance with an ‘entropic grid’, the under-storey of which hosts a carefully managed system of short-rotation coppice (SRC). The coppice, a medieval practice related to energy, product, and space, operates on theoretical and programmatic levels. It is planted along a structure of linear bunds, stabilized through coppice pole retaining structures and enriched with nutrients from coppice produced bio-char. Above the coppice is built an upper-storey of photovoltaic (PV); its structures fabricated from the coppiced timber and the PV produced with graphene from coppice charcoal processes.

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Burning seaweed to produce kelp, valued for its high potash and soda content, was formerly a significant industry in remote coastal areas of Scotland and elsewhere. Given the high concentrations of arsenic in seaweeds, up to 100 mg kg(-1), this study investigates the possibility that the kelp industry caused arsenic contamination of these pristine environments. A series of laboratory-scale seaweed burning experiments was conducted, and analysis of the products using HPLC ICP-MS shows that at least 40% of the arsenic originally in the seaweed could have been released into the fumes. The hypothesis that the burning process transforms arsenic from low toxicity arsenosugars in the original seaweeds (Fucus vesiculosus and Laminaria digitata) to highly toxic inorganic forms, predominantly arsenate, is consistent with As speciation analysis results. A field study conducted on Westray, Orkney, once a major centre for kelp production, shows that elevated arsenic levels (10.7+/-3.0 mg kg(-1), compared to background levels of 1.7+/-0.2 mg kg(-1)) persist in soils in the immediate vicinity of the kelp burning pits. A model combining results from the burning experiments with data from historical records demonstrates the potential for arsenic deposition of 47 g ha(-1) year(-1) on land adjacent to the main kelp burning location on Westray, and for arsenic concentrations exceeding current UK soil guideline values during the 50 year period of peak kelp production.

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Increasing energy consumption has exerted great pressure on natural resources; this has led to a move towards sustainable energy resources to improve security of supply and to reduce greenhouse gas emissions. However, the rush to the cure may have been made in haste. Biofuels in particular, have a bad press both in terms of competition with good agricultural land for food, and also in terms of the associated energy balance with the whole life cycle analysis of the biofuel system. The emphasis is now very much on sustainable biofuel production; biofuels from wastes and lignocellulosic material are now seen as good sustainable biofuels that affect significantly better greenhouse gas balances as compared with first generation biofuels. Ireland has a significant resource of organic waste that could be a potential source of energy through anaerobic digestion. Ireland has 8% of the cattle population of the EU with less than 1% of the human population; as a result 91% of agricultural land in Ireland is under grass. Residues such as slurries and slaughter waste together with energy crops such as grass have an excellent potential to produce biogas that may be upgraded to biomethane. This biomethane may be used as a natural gas substitute; bio-compressed natural gas may then be an avenue for a biofuel strategy. It is estimated that a maximum potential of 33% of natural gas may be substituted by 2020 with a practical obtainable level of 7.5% estimated. Together with biodiesel from residues the practical obtainable level of this strategy may effect greater than a 5% substitution by energy of transport. The residues considered in this strategy to produce biofuel (excluding grass) have the potential to save 93,000 ha of agricultural land (23% of Irish arable land) when compared to a rapeseed biodiesel strategy. © 2009 Elsevier Ltd. All rights reserved.

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Here we present the first high-resolution multi-proxy analysis of a rich fen in the central-eastern European lowlands. The fen is located in the young glacial landscape of the Sta{ogonek}zki river valley. We investigated the fen's development pathways, asking three main questions: (i) what was the pattern and timing of the peatland's vegetation succession, (ii) how did land use and climate affect the succession in the fen ecosystem, and (iii) to what degree does the reconstructed hydrology for this site correlate with those of other sites in the region in terms of past climate change? Several stages of fen history were determined, beginning with the lake-to-fen transition ca. AD 700. Brown mosses dominated the sampling site from this period to the present. No human impact was found to have occurred until ca. AD 1700, when the first forest cutting began. Around AD 1890 a more significant disturbance took place-this date marks the clear cutting of forests and dramatic landscape openness. Deforestation changed the hydrology and chemistry of the mire, which was revealed by a shift in local plant and testate amoebae communities. We also compared a potential climatic signal recorded in the peat profile before AD 1700 with other sites from the region. © 2013 John Wiley & Sons, Ltd.

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1. Quantitative reconstruction of past vegetation distribution and abundance from sedimentary pollen records provides an important baseline for understanding long term ecosystem dynamics and for the calibration of earth system process models such as regional-scale climate models, widely used to predict future environmental change. Most current approaches assume that the amount of pollen produced by each vegetation type, usually expressed as a relative pollen productivity term, is constant in space and time.
2. Estimates of relative pollen productivity can be extracted from extended R-value analysis (Parsons and Prentice, 1981) using comparisons between pollen assemblages deposited into sedimentary contexts, such as moss polsters, and measurements of the present day vegetation cover around the sampled location. Vegetation survey method has been shown to have a profound effect on estimates of model parameters (Bunting and Hjelle, 2010), therefore a standard method is an essential pre-requisite for testing some of the key assumptions of pollen-based reconstruction of past vegetation; such as the assumption that relative pollen productivity is effectively constant in space and time within a region or biome.
3. This paper systematically reviews the assumptions and methodology underlying current models of pollen dispersal and deposition, and thereby identifies the key characteristics of an effective vegetation survey method for estimating relative pollen productivity in a range of landscape contexts.
4. It then presents the methodology used in a current research project, developed during a practitioner workshop. The method selected is pragmatic, designed to be replicable by different research groups, usable in a wide range of habitats, and requiring minimum effort to collect adequate data for model calibration rather than representing some ideal or required approach. Using this common methodology will allow project members to collect multiple measurements of relative pollen productivity for major plant taxa from several northern European locations in order to test the assumption of uniformity of these values within the climatic range of the main taxa recorded in pollen records from the region.

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Lead (Pb) is a non-threshold toxin capable of inducing toxic effects at any blood level but availability of soil screening criteria for assessing potential health risks is limited. The oral bioaccessibility of Pb in 163 soil samples was attributed to sources through solubility estimation and domain identification. Samples were extracted following the Unified BARGE Method. Urban, mineralisation, peat and granite domains accounted for elevated Pb concentrations compared to rural samples. High Pb solubility explained moderate-high gastric (G) bioaccessible fractions throughout the study area. Higher maximum G concentrations were measured in urban (97.6 mg kg−1) and mineralisation (199.8 mg kg−1) domains. Higher average G concentrations occurred in mineralisation (36.4 mg kg−1) and granite (36.0 mg kg−1) domains. Findings suggest diffuse anthropogenic and widespread geogenic contamination could be capable of presenting health risks, having implications for land management decisions in jurisdictions where guidance advises these forms of pollution should not be regarded as contaminated land.

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Land wars in India: Contestations, social forces and evolving neoliberal urban transformation
The recent incidents of ‘land wars’ in India have highlighted the contradictions and challenges of the neoliberal urban transformation through a range of issues across governance, equity and empowerment in the development agenda. Simply put, a strong top down approach and corporate-political nexus have determined the modality of land acquisition, compensation and ultimately the nature of its consumption leaving out majority urban poor from its benefits. The paper focuses on the concept of neoliberalism as a modality of urban governance and emergence of the grassroots activism as a countermagnate to neoliberalist hegemony by examining the inequity and marginalization that embody these ‘land wars’ in India and the forms of resistance from the grassroots - their capacity, relationship and modus operandi. Emerging lessons suggest the potential for advancing governance from the bottoms up leading to more equitable distribution of resources. It is however argued that there is a need for a stronger conception of the ‘grassroots’ in both epistemological and empirical context. In particular, the preconditions for the ‘grassroots organisations’ to foster and play a more effective role requires a more inclusive notion of ‘institutionality and plurality’ within the current political economic context. The empirical focus of the paper is ‘land wars’ observed in Kolkata, West Bengal, however references to other examples across the country have also been made.

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Despite the appeal and significance of nationalism as a near universal political force, Irish historians – in common with the historians of most nationalist movements – have struggled to analyse nationalism from beyond the perspective of the nation state. The reasons for this are varied, arising both from practical aspects, such as the availability and accessibility of sources, to more conceptual issues such as the resilience of the national perspective in the framing of historiographical narratives. This paper considers the Easter Rising as a case study in assessing how a transnational framework complicates traditional historiographical perspectives. Accounts of the Easter Rising generally interpret the rebellion within local, national, or international (particularly Anglo-Irish or imperial) frameworks. Interpretations that adopt a broader framework have tended to focus on international rather than transnational dimensions: the First World War context, revolutionary links with Germany, and the role of the United States. This paper assesses the potential of a transnational approach by analysing four aspects of the Rising: the significance of the transnational movement of people prior to the event; the influence of the transnational circulation of political ideas; the impact of transnational cultural currents in shaping the framing of revolutionary ideals; and the impact of the Rising on Irish nationalist communities beyond Ireland.

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PURPOSE. To explore factors potentially influencing the success or failure of rural Chinese hospitals in increasing cataract surgical output and quality. METHODS. Focus groups (FGs, n = 10) were conducted with hospital administrators, doctors, and nurses at 28 county hospitals in Guangdong Province. Discussions explored respondents' views on increasing surgical volume and quality and improving patient satisfaction. Respondents numerically ranked possible strategies to increase surgical volume and quality and patient satisfaction. FG transcripts were independently coded by two reviewers utilizing the constant comparative method following the grounded theory approach, and numerical responses were scored and ranked. RESULTS. Ten FGs and 77 ranking questionnaires were completed by 33 administrators, 23 doctors, and 21 nurses. Kappa values for the two coders were greater than 0.7 for all three groups. All groups identified a critical need for enhanced management training for hospital directors. Doctors and nurses suggested reducing surgical fees to enhance uptake, although administrators were resistant to this. Although doctors saw the need to improve equipment, administrators felt current material conditions were adequate. Respondents agreed that patient satisfaction was generally high, and did not view increasing patient satisfaction as a priority. CONCLUSIONS. Our findings highlight agreements and disagreements among the three stakeholder groups about improving surgical output and quality, which can inform strategies to improve cataract programs in rural China. Respondents' beliefs about high patient satisfaction are not in accord with other studies in the area, highlighting a potential area for intervention. © 2013 The Association for Research in Vision and Ophthalmology, Inc.

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Tese de doutoramento, Ciências Geofísicas e da Geoinformação (Deteção Remota), Universidade de Lisboa, Faculdade de Ciências, 2015

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Fungi belonging to the genus of Alternaria are recognised as being significant plant pathogens, and Alternaria allergens are one of themost important causes of respiratory allergic diseases in Europe. This study aims to provide a detailed and original analysis of Alternaria transport dynamics in Badajoz, SW Spain. This was achieved by examining daily mean and hourly observations of airborne Alternaria spores recorded during days with high airborne concentrations of Alternaria spores (N100 s m−3) from 2009 to 2011, as well as four inventory maps of major Alternaria habitats, the overall synoptic weather situation and analysis of air mass transport using Hybrid Single Particle Lagrangian Integrated Trajectory model and geographic information systems. Land use calculated within a radius of 100 km from Badajoz shows that crops and grasslands are potentially the most important local sources of airborne Alternaria spores recorded at the site. The results of back trajectory analysis showthat, during the examined four episodes, the two main directions where Alternaria source areas were located were: (1) SW–W; and (2) NW–NE. Regional scale and long distance transport could therefore supplement the airborne catch recorded at Badajoz with Alternaria conidia originating from sources such as crops and orchards situated in other parts of the Iberian Peninsula.

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Following the 1978 rural reform, a series of agricultural reforms were introduced in China with an aim to create incentives for the farmers to produce more. However, the nineties’ reforms towards liberalization eventually resulted in a huge drop in agricultural production, which apparently motivated the grain self-sufficiency program in 1998. For a dataset that covers wheat production during these reforms, we examine how and to what extent these reforms affected the Total Factor Productivity (TFP) and the welfare of wheat farmers in China, both at the national and at the regional level. We find that although the nineties' price reforms led to a relatively faster growth of the incentivized TFP of wheat production, they failed to improve profits vis a vis welfare for the farmers. A series of weather shocks in the early nineties resulted in a scarcity of cultivable land and a shortage of agricultural labour, which eventually led to a sharp increase in their relative prices. The introduction of grain self-sufficiency program stabilized these agricultural prices but destroyed the growth in TFP for most regions. However, this reform resulted in some improvement in farmers’ welfare. Wheat farmers in China therefore experienced a trade off between productivity and welfare; competition boosted their productivity and regulation improved their welfare. Not only these findings add a completely new set of results to the existing literature, they can also form a strong basis for future agricultural reforms in China.

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Are return migrants more productive than non-migrants? If so, is it a causal effect or simply self-selection? Existing literature has not reached a consensus on the role of return migration for origin countries. To answer these research questions, an empirical analysis was performed based on household data collected in Cape Verde. One of the most common identification problems in the migration literature is the presence of migrant self-selection. In order to disentangle potential selection bias, we use instrumental variable estimation using variation provided by unemployment rates in migrant destination countries, which is compared with OLS and Nearest Neighbor Matching (NNM) methods. The results using the instrumental variable approach provide evidence of labour income gains due to return migration, while OLS underestimates the coefficient of interest. This bias points towards negative self-selection of return migrants on unobserved characteristics, although the different estimates cannot be distinguished statistically. Interestingly, migration duration and occupational changes after migration do not seem to influence post-migration income. There is weak evidence that return migrants from the United States have higher income gains caused by migration than the ones who returned from Portugal.

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The present work project studies the next step in the internationalization process of Shoyce, the soy milk products brand of Nutre. In order to select the best target market in the Asia-Pacific for Nutre to export, a sequential screening process was developed using two complementary approaches: preliminary country screening and country ranking, followed by an in-depth analysis of the country ranking first. The analysis revealed Japan as the most attractive country for Shoyce’s international expansion. Potential entry modes in the Japanese soy milk market were then evaluated, whereby direct exporting via a local distributor was found to be the most appropriate.