56 research outputs found

    Local Consequences of Global Uncertainty: Capacity Development and LNG Trade Under Shale Gas and Demand Uncertainty and Disruption Risk

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    Recent supply security concerns in Europe have revived interest into the natural gas market. Here, we investigate investment behavior and trade in an imperfect market structure under uncertainty in both supply and demand. We focus on three uncertain events: i) transit of Russian gas via Ukraine that may be disrupted from 2020 on; ii) natural gas intensity of electricity generation in OECD countries that may lead to higher or lower natural gas demand after 2025; and iii) availability of shale gas around the globe after 2030. We illustrate how timing of investments is affected by inter-temporal hedging behavior of market agents, such as when LNG capacity provides ex-ante flexibility (e.g., in Ukraine to hedge for a possible Russian supply disruption) or an expost fallback option if domestic or nearby pipeline supply sources are low (e.g., uncertain shale gas resources in China). Moreover, we find that investment in LNG capacities is more determined by demand side pull (due to higher needs in electric power generation) than by supply side push (higher shale gas supplies needing an outlet)

    Analysis of obstetric complications and uterine connective tissue in tenascin-X-deficient humans and mice

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    Tenascin-X (TNX) is a large, multi-domain, extracellular matrix glycoprotein. Complete deficiency of TNX in humans leads to a recessive form of Ehlers-Danlos syndrome (EDS), and TNX haploinsufficiency is a cause of hypermobility type EDS. EDS patients appear to have a higher risk of several complications during pregnancy, such as pelvic instability, premature rupture of membranes, and postpartum hemorrhage. Here, we present a study of genitourinary and obstetric complications in TNX-deficient women of reproductive age. We have found complications, such as uterus prolapses, that are in agreement with previous findings in other EDS types. In TNX knockout (KO) mice, we have observed mild pregnancy-related abnormalities. Morphological and immunohistological analysis of uterine tissues has not revealed obvious quantitative or spatial differences between TNX KO and wildtype mice with respect to collagen types I, III, V, and XII or elastic fibers. We conclude that TNX-deficient women are at risk of obstetric complications, but that TNX KO mice show only a mild phenotype. Furthermore, we show that TNX is involved in the stability of elastic fibers rather than in their initial deposition

    A western gray whale mitigation and monitoring program for a 3-D seismic survey, Sakhalin Island, Russia

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    The introduction of anthropogenic sounds into the marine environment can impact some marine mammals. Impacts can be greatly reduced if appropriate mitigation measures and monitoring are implemented. This paper concerns such measures undertaken by Exxon Neftegas Limited, as operator of the Sakhalin-1 Consortium, during the Odoptu 3-D seismic survey conducted during 17 August’ September 2001. The key environmental issue was protection of the critically endangered western gray whale (Eschrichtius robustus), which feeds in summer and fall primarily in the Piltun feeding area off northeast Sakhalin Island. Existing mitigation and monitoring practices for seismic surveys in other jurisdictions were evaluated to identify best practices for reducing impacts on feeding activity by western gray whales. Two buffer zones were established to protect whales from physical injury or undue disturbance during feeding. A 1 km buffer protected all whales from exposure to levels of sound energy potentially capable of producing physical injury. A 4’ km buffer was established to avoid displacing western gray whales from feeding areas. Trained Marine Mammal Observers (MMOs) on the seismic ship Nordic Explorer had the authority to shut down the air guns if whales were sighted within these buffers

    Evidence of Market Power in the Atlantic Steam Coal Market Using Oligopoly Models with a Competitive Fringe

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    Before 2004 South Africa was the dominant steam coal exporter to the European market. However a new market situation with rising global demand and prices makes room for a new entrant: Russia. The hypothesis investigated in this paper is that the three incumbent dominant firms located in South Africa and Colombia reacted to that new situation by exerting market power and withheld quantities from the market in 2004 and 2005. Three market structure scenarios of oligopoly with a competitive fringe are developed to investigate this hypothesis: a Stackelberg model with a cartel, a Stackelberg model with a Cournot-oligopoly as leader and a Nash-bargaining model. The model with a Cournot oligopoly as leader delivers the best reproduction of the actual market situation meaning that the dominant players exert market power in a non-cooperative way without profit sharing. Furthermore some methodological clarifications regarding the modeling of markets with dominant players and a competitive fringe are made. In particular we show that the use of mixed aggregated conjectural variations can lead to outcomes that are inconsistent with the actions of rational profit-maximizing players

    The Role of CO2-EOR for the Development of a CCTS Infrastructure in the North Sea Region: A Techno-Economic Model and Application

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    Scenarios of future energy systems attribute an important role to Carbon Capture, Transport, and Storage (CCTS) in achieving emission reductions. Using captured CO2 for enhanced oil recovery (CO2-EOR) can improve the economics of the technology. This paper examines the potential for CO2-EOR in the North Sea region. UK oil fields are found to account for 47% of the estimated additional recovery potential of 3739 Mbbl (1234 MtCO2 of storage potential). Danish and Norwegian fields add 28% and 25%, respectively. Based on a comprehensive dataset, the paper develops a unique techno-economic market equilibrium model of CO2 supply from emission sources and CO2 demand from CO2-EOR to assess implications for a future CCTS infrastructure. A detailed representation of decreasing demand for fresh CO2 for CO2-EOR operation is accomplished via an exponential storage cost function. In all scenarios of varying CO2 and crude oil price paths the assumed CO2-EOR potential is fully exploited. CO2-EOR does add value to CCTS operations but the potential is very limited and does not automatically induce long term CCTS activity. If CO2 prices stay low, little further use of CCTS can be expected after 2035

    Comparison between human fetal and adult skin

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    Healing of early-gestation fetal wounds results in scarless healing. Since the capacity for regeneration is probably inherent to the fetal skin itself, knowledge of the fetal skin composition may contribute to the understanding of fetal wound healing. The aim of this study was to analyze the expression profiles of different epidermal and dermal components in the human fetal and adult skin. In the human fetal skin (ranging from 13 to 22 weeks’ gestation) and adult skin biopsies, the expression patterns of several epidermal proteins (K10, K14, K16, K17, SKALP, involucrin), basement membrane proteins, Ki-67, blood vessels and extracellular matrix proteins (fibronectin, chondroitin sulfate, elastin) were determined using immunohistochemistry. The expression profiles of K17, involucrin, dermal Ki-67, fibronectin and chondroitin sulfate were higher in the fetal skin than in adult skin. In the fetal skin, elastin was not present in the dermis, but it was found in the adult skin. The expression patterns of basement membrane proteins, blood vessels, K10, K14, K16 and epidermal Ki-67 were similar in human fetal skin and adult skin. In this systematic overview, most of the differences between fetal and adult skin were found at the level of dermal extracellular matrix molecules expression. This study suggests that, especially, dermal components are important in fetal scarless healing

    Analysis of the World Market for Steam Coal Using a Complementarity Model

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    With its resource availability and the prospect of climate friendly technology, coal continues to play an important role in the global energy sector. We develop a complementarity model of the international market for steam coal. We want to analyze the level of competition in this market which is strategic for the importers' security of energy supply. In a spatial equilibrium framework, we assume the steam coal exporters to maximize their profits by choosing the optimal quantity to sell to each importing country. We compare two possible scenarios: perfect competition and Cournot competition. The results, especially the price levels, indicate that the Cournot model is not realistic, suggesting that the producing countries do not exert market power. However, the trade flows and prices observed in reality suggests that there is some form of market power with price discrimination, possibly following a Bertrand model in a spatial setting

    Endogenous Shifts in OPEC Market Power: A Stackelberg Oligopoly with Fringe

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    This article proposes a two-stage oligopoly model for the crude oil market. In a game of several Stackelberg leaders, market power increases endogenously as the spare capacity of the competitive fringe goes down. This effect is due to the specific cost function characteristics of extractive industries. The model captures the increase of OPEC market power before the financial crisis and its drastic reduction in the subsequent turmoil at the onset of the global recession. The two-stage model better replicates the price path over the years 2003-2011 than a standard simultaneous-move, one-stage Nash-Cournot model with a fringe. I also discuss how most large-scale numerical equilibrium models, widely applied in the energy sector, over-simplify and misinterpret market power exertion. Furthermore, I show that this two-stage Stackelberg model can be solved numerically as a Mixed Complementarity Problem with heterogeneous firms and discuss uniqueness

    A Place to Rest Your (Burnt) Bones? Mortuary Houses in Early Anglo-Saxon England

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    This is an Accepted Manuscript of an article published by Taylor & Francis in Archaeological Journal on 5th October 2017, available online: doi: 10.1080/00665983.2017.1366704This article presents a fresh interpretation of square and rectangular mortuary structures found in association with deposits of cremated material and cremation burials in a range of early Anglo-Saxon (fifth-/sixth-century AD) cemeteries across southern and eastern England. Responding to a recent argument that they could be traces of pyre structures, a range of ethnographic analogies are drawn upon, and the full-range of archaeological evidence is synthesized, to re-affirm and extend their interpretation as unburned mortuary structures. Three interleaving significances are proposed: (i) demarcating the burial place of specific individuals or groups from the rest of the cemetery population, (ii) operating as ‘columbaria’ for the above-ground storage of the cremated dead (i.e. not just to demarcate cremation burials), and (iii) providing key nodes of commemoration between funerals as the structures were built, used, repaired and eventually decayed within cemeteries. The article proposes that timber ‘mortuary houses’ reveal that groups in early Anglo-Saxon England perceived their cemeteries in relation to contemporary settlement architectures, with some groups constructing and maintaining miniaturized canopied buildings to store and display the cremated remains of the dead
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