86 research outputs found
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Modelling sediment supply and transport in the River Lugg: strategies for controlling sediment loads
The River Lugg has particular problems with high sediment loads that have resulted in detrimental impacts on ecology and fisheries. A new dynamic, process-based model of hydrology and sediments (INCA- SED) has been developed and applied to the River Lugg system using an extensive data set
from 1995–2008. The model simulates sediment sources and sinks throughout the catchment and gives a good representation of the sediment response at 22 reaches along the River Lugg. A key question considered in using the model is the management of sediment sources so that concentrations and bed loads can be reduced in the river system. Altogether, five sediment management scenarios were selected for testing on the River Lugg, including land use change, contour tillage, hedging and buffer strips. Running the model with parameters altered to simulate these five scenarios produced some interesting results. All scenarios achieved some reduction in sediment levels, with the 40% land use change achieving the best result with a 19% reduction. The other scenarios also achieved significant reductions of between 7% and 9%. Buffer strips produce the best result at close to 9%. The results suggest that if hedge introduction, contour tillage and buffer strips were
all applied, sediment reductions would total 24%, considerably improving the current sediment situation. We present a novel cost-effectiveness analysis of our results where we use percentage of land removed from production as our cost function. Given the minimal loss of land associated
with contour tillage, hedges and buffer strips, we suggest that these management practices are the most cost-effective combination to reduce sediment loads
Mapping The Emerging Strategic Stability And Arms Control Landscape
• Our nuclear world is changing, and this will have significant impacts on strategic stability and arms control. This is being driven by a mixture of technological, geopolitical and normative forces. • Technological change and innovation are facilitating new types of strategic weaponry and missions. These have the potential to challenge established notions of deterrence and create nuclear risks. • The combination of an emerging system of nuclear great-power multipolarity at the same time as a growth in “nuclear nationalism” and a return of bellicose nuclear rhetoric and statecraft are challenging traditional power balances, arms control and nuclear stability based on restraint. • This is all taking place within a bifurcating global nuclear environment characterised on one side by normative challenges to the established nuclear order and increasing demands for nuclear energy, and on the other with a resurgence in the political salience of nuclear weapons. • Taken together, this suggests that we are arguably on the cusp of a new “nuclear age” where we will need to rethink the rules of the nuclear game and how we prevent nuclear use.Mapping The Emerging Strategic Stability And Arms Control LandscapepublishedVersio
Questioning the holy trinity:Why the U.S. nuclear triad stillmakes sense
Despite renewed enthusiasm for nuclear disarmament, a contemporary security environment far removed from that of the Cold War, and increasing budgetary pressures at home, U.S. interests continue to be best served by retaining a triad of nuclear forces. While options for a reduced force structure may appear to offer short-term political and economic expediency, in the long run a three-legged deterrent-possibly consisting of fewer delivery vehicles, operational warheads and even potentially de-alerted forces-represents the best way to balance the competing requirements of contemporary and future U.S. nuclear policy. Indeed, itmay be that retaining the triad provides the most realistic method of reestablishing U.S.-Russia strategic stability, and the most credible basis for advancing the drive for global nuclear reductions, strengthening global nuclear security, and even working toward nuclear abolition.</p
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Controls on inorganic nitrogen leaching from Finnish catchments assessed using a sensitivity and uncertainty analysis of the INCA -N model
The semi-distributed, dynamic INCA-N model was used to simulate the behaviour of dissolved inorganic nitrogen (DIN) in two Finnish research catchments. Parameter sensitivity and model structural uncertainty were analysed using generalized sensitivity analysis. The Mustajoki catchment is a forested upstream catchment, while the Savijoki catchment represents intensively cultivated lowlands. In general, there were more influential parameters in Savijoki than Mustajoki. Model results were sensitive to N-transformation rates, vegetation dynamics, and soil and river hydrology. Values of the sensitive parameters were based on long-term measurements covering both warm and cold years. The highest measured DIN concentrations fell between minimum and maximum values estimated during the uncertainty analysis. The lowest measured concentrations fell outside these bounds, suggesting that some retention processes may be missing from the current model structure. The lowest concentrations occurred mainly during low flow periods; so effects on total loads were small
Strategic non-nuclear weapons and the onset of a Third Nuclear Age
Three decades after what is widely referred to as the transition from a First to a Second Nuclear Age, the world stands on the cusp of a possible Third Nuclear Age where the way that we conceptualise the central dynamics of the nuclear game will change again. This paradigm shift is being driven by the growth and spread of non-nuclear technologies with strategic applications and by a shift in thinking about the sources of nuclear threats and how they should be addressed, primarily, but not solely, in the United States. Recent scholarship has rightly identified a new set of challenges posed by the development of strategic non-nuclear weaponry (SNNW). But the full implications of this transformation in policy, technology and thinking for the global nuclear order as a whole have so far been underexplored. To remedy this, we look further ahead to the ways in which current trends, if taken to their logical conclusion, have the capacity to usher in a new nuclear era. We argue that in the years ahead, SNNW will increasingly shape the nuclear order, particularly in relation to questions of stability and risk. In the Third Nuclear Age, nuclear deployments, postures, balances, arms control, non-proliferation policy, and the prospects for disarmament, will all be shaped as much by developments in SNNW capabilities as by nuclear weapons. Consequently, we advocate for an urgent reassessment of the way nuclear order and nuclear risks are conceptualised as we confront the challenges of a Third Nuclear Age
The Global Third Nuclear Age:Clashing Visions for a New Era in International Politics
This book provides an in-depth examination of the technological, geopolitical and normative pressures driving the world into a new, more complex and potentially more dangerous Third Nuclear Age. By adopting an innovative framework for analysis, the book challenges the constrained focus of much of the existing literature by explaining that the pathways to nuclear security for different actors across the globe will vary considerably in this new context. It argues that the Third Nuclear Age will be defined by friction and conflict between “Nuclear Traditionalists,” “Technological Transformers,” “Hedgers and Balancers” and “Activists and Protestors,” as different interests and visions of the nuclear future clash. The book draws on dozens of interviews and non-English language sources to provide a global approach and looks at the security politics driving the political debate in 20 different countries across the globe. This book will be of much interest to students of nuclear politics, security studies and International Relations.</p
The Global Third Nuclear Age
This book provides an in-depth examination of the technological, geopolitical and normative pressures driving the world into a new, more complex and potentially more dangerous Third Nuclear Age.
By adopting an innovative framework for analysis, the book challenges the constrained focus of much of the existing literature by explaining that the pathways to nuclear security for different actors across the globe will vary considerably in this new context. It argues that the Third Nuclear Age will be defined by friction and conflict between “Nuclear Traditionalists,” “Technological Transformers,” “Hedgers and Balancers,” and “Activists and Protestors,” as different interests and visions of the nuclear future clash. The book draws on dozens of interviews and non-English language sources to provide a global approach and looks at the security politics driving the political debate in 20 different countries across the globe.
This book will be of much interest to students of nuclear politics, security studies and International Relations.
The Open Access version of this book, available at www.taylorfrancis.com, has been made available under a Creative Commons Attribution-Non Commercial-No Derivatives (CC-BY-NC-ND) 4.0 license
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False positive and false negative errors in the design and implementation of agri-environmental policies: a case study on water quality and agricultural nutrients
When designing and implementing agri-environmental policies to reduce nutrient loss, action programmes may falsely address areas where the nutrient issue from agricultural activity is not currently important and is not likely to become so in the future (a false positive), or may fail to address areas where the agricultural nutrient issue is currently important or may likely become so in the future (a false negative). Based on a case study of the Louros watershed in Greece, this work identifies database and modelling sources of false positives and negatives and proposes a decision making process aimed at minimizing the possibility of committing such errors. The baseline is well simulated and shows that the Louro’s watershed falls behind a Good Environmental Status, at least marginally. Simulated mitigation measures show that the river’s status can be upgraded to “Good”, at least as concerns nitrates and ammonium. Simulated climate change does not seem to exert an important positive or negative effect. Land use changes forecasting considerably less cultivated area have a significant effect on Total Phosphorous but not on nitrates or ammonium concentrations. The non-linearity between nutrient disposition (inputs) and nutrient concentration in downstream water bodies (output) and the many factors that affect the nutrient disposition-transportation-concentration chain, highlights the importance of simulating the effects of mitigation actions and of future climate and land use changes before adopting and establishing agri-environmental measures
Trends and patterns in surface water chemistry in Europe and North America between 1990 and 2020, with a focus on calcium
Prosjektleder: Rolf David VogtThe report presents trends in major anions and cations, pH, TOC and bicarbonate in surface waters in Europe and North America from 1990 to 2020. Special attention is given to trends in calcium, which showed some unexpected increases. The trends in calcium are analysed in relation to changes in bicarbonates, organic anions, and deposition loads. The surface waters show strong signs of chemical recovery.Norwegian Ministry of Climate and Environment, United Nations Economic Commission for Europe (UNECE)publishedVersio
Oxidized cholesteryl ester induces exocytosis of dysfunctional lysosomes in lipidotic macrophages
Funding Information: This work was financially supported by FCT (Foundation for Science and Technology of the Portuguese Ministry of Science and Higher Education) through national funds and co‐funded by FEDER under the PT2020 Partnership (Ref. PTDC/MED‐PAT/29395/2017, 2022.01305.PTDC and 2022.03249.PTDC). The Coimbra Chemistry Center (CQC) is supported by the FCT through Project UID/QUI/00313/2019. MSCA‐RISE: “Genetic and Small Molecule Modifiers of Lysosomal Function” (LysoMod), financed by Horizon 2020. Ref 734825. Twinning on “Excel in Rare Diseases' Research: Focus on LYSOsomal Disorders and CILiopathies”, Ref (H2020‐TWINN‐2017: GA 81108). Neuza Domingues was a holder of PhD fellowship from the FCT (Ref. No: SFRH/BD/51877/2012), attributed by Inter‐University Doctoral Programme in Ageing and Chronic Disease (PhDOC). André R.A. Marques was funded by the FCT Stimulus of Scientific Employment Individual Support Call 2017 (CEECIND/01006/2017). Rosa Puertollano was funded by the NHLBI Division of Intramural Research (ZIA HL006151‐10). Publisher Copyright: © 2023 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.A key event in atherogenesis is the formation of lipid-loaded macrophages, lipidotic cells, which exhibit irreversible accumulation of undigested modified low-density lipoproteins (LDL) in lysosomes. This event culminates in the loss of cell homeostasis, inflammation, and cell death. Nevertheless, the exact chemical etiology of atherogenesis and the molecular and cellular mechanisms responsible for the impairment of lysosome function in plaque macrophages are still unknown. Here, we demonstrate that macrophages exposed to cholesteryl hemiazelate (ChA), one of the most prevalent products of LDL-derived cholesteryl ester oxidation, exhibit enlarged peripheral dysfunctional lysosomes full of undigested ChA and neutral lipids. Both lysosome area and accumulation of neutral lipids are partially irreversible. Interestingly, the dysfunctional peripheral lysosomes are more prone to fuse with the plasma membrane, secreting their undigested luminal content into the extracellular milieu with potential consequences for the pathology. We further demonstrate that this phenotype is mechanistically linked to the nuclear translocation of the MiT/TFE family of transcription factors. The induction of lysosome biogenesis by ChA appears to partially protect macrophages from lipid-induced cytotoxicity. In sum, our data show that ChA is involved in the etiology of lysosome dysfunction and promotes the exocytosis of these organelles. This latter event is a new mechanism that may be important in the pathogenesis of atherosclerosis.publishersversionpublishe
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