Emerging Role of Atmospheric Nitrogen Deposition in Coastal Eutrophication: Biogeochemical and Trophic Perspectives

1993 ◽  
Vol 50 (10) ◽  
pp. 2254-2269 ◽  
Author(s):  
Hans W. Paerl
Keyword(s):  
Nutrient Loading ◽  
Western Mediterranean ◽  
Atmospheric Nitrogen ◽  
Nutrient Inputs ◽  
New Production ◽  
Atlantic Seaboard ◽  
Trophic Changes ◽  
The Baltic ◽  
Temporal Interactions

Approximately half of the world's oceanic primary production originates in coastal waters which are often nitrogen (N) limited and sensitive to externally supplied N. Among anthropogenically generated N sources, atmospheric deposition of N (ADN) (as wet- and dryfall) contributes 10–50% of the total external N load at present (20–100 mmol N∙m−2∙yr−1), and this will increase. At current levels, atmospheric N inputs lead to a significant enhancement of CO2 fixation and chlorophyll a production. ADN may play a central role in mediating "new" production in coastal oceans downwind of emissions. Alterations in productivity, nutrient flux, and trophic changes have recently been documented from the Baltic and North seas, the Northwest Atlantic seaboard, and the Western Mediterranean. The recently noted "epidemic" of toxic and nuisance phytoplankton blooms is possibly due to accelerating nutrient loading inshore, especially from atmospheric sources. A need exists to spatially and temporally evaluate, quantify, and potentially manage this nutrient-production interaction on regional and larger synoptic scales. Aircraft- and satellite-based multiband ocean color remote sensing (SeaWiFS) will help characterize and link the spatial-temporal interactions of this (and other) "new" nutrient inputs with biogeochemical and trophic changes in coastal and offshore waters.

scholarly journals The Role of a Permeable Sand Column in Modifying Tidal Creek Nutrient Inputs into the Coastal Ocean

Water ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3079
Author(s):  
Nicholas A. Legut ◽  
Brandon T. Hawkins ◽  
Angelos K. Hannides
Keyword(s):  
South Carolina ◽  
Nutrient Loading ◽  
Salinity Gradient ◽  
Coastal Ocean ◽  
Coastal Sediments ◽  
Nutrient Inputs ◽  
Tidal Creeks ◽  
Overlying Water ◽  
Sand Column

Estuarine tidal creeks are an important conduit for freshwater run-off into the coastal ocean. In Long Bay, South Carolina, tidal creeks terminate in swashes—broad sandy fields constantly reworked by discharged creek water. We examined the role of a highly permeable sandy column in altering the nutrient loading of the passing water at Singleton Swash, Myrtle Beach, South Carolina. Seasonal transects along the swash’s primary channel documented gradients in physical and biogeochemical parameters. The nutrient and chlorophyll a concentrations were higher in the sediment than in the overlying water, consistent with coastal sediments as a major site of organic matter degradation, nutrient regeneration, and benthic primary productivity. Oxygen, nutrient, and chlorophyll concentrations exhibited a strong seasonal component, explained by a photosynthesis–respiration balance shift between summer and winter. The conservative mixing model approach to elucidate the sink–source patterns was moderately informative due to the lack of a gradual salinity gradient from land to ocean, due to substantial tidal flushing and observable nutrient-rich surface freshwater discharges along the channel that fueled substantial submerged aquatic macroalgal growth. Future studies should focus on the role of benthic photosynthesizers, both microbial and macroalgal, in retaining land-derived nutrients in irrigation freshwater inputs prior to them reaching the coastal ocean.

scholarly journals Internet of Vehicles Empowered Mobile Media: Research on Mobile-Generated Content (MoGC) for Intelligent Connected Vehicles

2021 ◽  
Vol 13 (6) ◽  
pp. 3538
Author(s):  
Zhiyuan Yu ◽  
Doudou Jin ◽  
Chao Zhai ◽  
Wan Ni ◽  
Desheng Wang
Keyword(s):  
Production Capacity ◽  
Professional Organizations ◽  
Connected Vehicles ◽  
New Production ◽  
Mobile Media ◽  
Internet Of Vehicles ◽  
News Source ◽  
Media Environments ◽  
Content Generation

With the rapid growth of mobile media, large quantities of mobile content have been generated by moving entities. Some content generation patterns become popular for users and professional organizations, e.g., user-generated content, professionally-generated content, machine-generated content. However, due to the limitations of device types and functions, it is necessary to explore the new production tools and further inspire the content potential in mobile scenarios. According to the production capacity supported by Internet of Vehicles, intelligent connected vehicles (ICVs) emerge as new content generated devices in sustainable cities. In this paper, we propose the concept of Mobile-Generated Content (MoGC) as a new part of production patterns. First, we analyze the relationship between MoGC and existing patterns from the perspectives of entity and workflow. Second, the unique functionality and social property of MoGC are revealed, i.e., ICVs play the role of middle platform with data and technology offices. The current dominant discourse created by the professional institutions (e.g., media agency or governing authority) will transfer to the vehicle users. In this way, the content generation system has been further enriched in omni-media environments through efficiently integrating productivity tools and resources. Besides, MoGC not only contributes to social governance by enlarging the news source and coverage, but also strengthen the personal discourse in mobile scenarios.

The role of a silicate pump in driving new production

1995 ◽  
Vol 42 (5) ◽  
pp. 697-719 ◽  
Author(s):  
Richard C. Dugdale ◽  
Frances P. Wilkerson ◽  
Hans J. Minas
Keyword(s):  
New Production

Corruption as a factor that hampers the socialization of the economy

2020 ◽  
pp. 112-119
Author(s):  
Olga B. Lemeshonok ◽  
Keyword(s):  
Institutional Environment ◽  
Economic Systems ◽  
New Production ◽  
The Public ◽  
Corruption Perception ◽  
Relations Of Power ◽  
Innovative Orientation ◽  
Power And Dependence ◽  
Dependence Property

The author investigates comparisons of the corruption prevalence in countries with different economic systems based on the regularly calculated corruption perception index. The essence of corruption interactions in an economy is revealed through relations of power and dependence, property distribution and related economic actors behavior. The article shows a role of the institutional environment in corruption expanding or reducing, its connection with the development of civil society and the processes of economy socialization. The influence of corruption on certain aspects of economy socialization is specified: social differentiation, innovative orientation of production development, macroeconomic stability, development of the institutional environment, efficiency of the public administration system, property allocation efficiency, general humanization of activities and the human capital quality associated with these processes. The author shows how corruption relations affect individual aspects of socialization of the economy, considers the potential and prospects of noonomy and the NIS’s new economy in the processes of reducing corruption and strengthening the foundations of socialization. Micro- and macroaspects of the formation of a new human with his needs structure and new production corresponding to these needs are separately noted.

HAS PSYCHOLOGIC MALNUTRITION TAKEN THE PLACE OF RICKETS AND SCURVY IN CONTEMPORARY PEDIATRIC PRACTICE?

PEDIATRICS ◽  
1963 ◽  
Vol 31 (6) ◽  
pp. 909-918
Author(s):  
Nathan B. Talbot
Keyword(s):  
Sixteenth Century ◽  
Lemon Juice ◽  
Climatic Conditions ◽  
Northern Europe ◽  
Scientific Medicine ◽  
Pediatric Practice ◽  
Therapeutic Value ◽  
High Prevalence ◽  
The Baltic

WHILE MEDICAL HISTORIANS cannot provide us with accurate statistics concerning the incidence of rickets and scurvy in centuries past, they leave little room for doubt about the high prevalence of these disorders prior to the advent of modern scientific medicine. Thus, Castiglione has written that in the sixteenth century scurvy raged throughout northern Europe, in Scandinavia, on the shores of the Baltic, and in the interior of Germany. It is interesting to note, however, that Jacques Cartier, whose sailors had been ravaged by scurvy, learned in 1536 from the Indians that the malady could be cured by juices of the almeda tree. This was 200 years before James Lind demonstrated the curative effects of lemon juice in his treatise on scurvy published in 1753 and almost 400 years before ascorbic acid, which was isolated by Szent-Gyorgi in 1928, was recognized to be vitamin C by Waugh and King in 1932. Rickets, likewise, was occurring in a large portion of children prior to the discovery of the existence of vitamin D by Hess, Steinbock, and Windaus in 1918, of its therapeutic value by Mellanby in 1919, of the equivalent role of sunlight by Hess in 1921, and of the chemical composition of the vitamins by Windaus in 1922. But 200 years earlier Friedrick Hoffman had the answer to the control of this disease almost in hand. He attached much importance to climatic conditions as a factor in rickets, noting that if anything is specially powerful in producing this affliction, it is a surrounding atmosphere of cold foggy air. He cited as striking evidence of this the famous emporium of England, London, which he found to be specially apt to produce and foster this disease.

External Threat and Democracy: The Role of NATO Revisited

2006 ◽  
Vol 43 (4) ◽  
pp. 413-431 ◽  
Author(s):  
Douglas M. Gibler ◽  
Jamil A. Sewell
Keyword(s):  
Regime Type ◽  
Baltic States ◽  
Democratic Transitions ◽  
Territorial Sovereignty ◽  
External Threat ◽  
The Baltic ◽  
Threat Levels ◽  
Determining Factor ◽  
Former Soviet Republics

This article examines the role of NATO in aiding democratic transitions and survival in the former Soviet republics. The authors argue that the level of external threat is a determining factor in centralization, militarization, and ultimately regime type. States tend to be democratic or are likely to make the transition toward democracy when threat levels are low, while autocracies are more likely to be found in states targeted by higher levels of threat. Building on recent findings examining the link between democracies and alliance, the authors demonstrate that NATO has been an effective guarantor of territorial sovereignty and independence in the Baltic states, Ukraine, and Moldova, reducing the level of threat experienced by each state, thus assuring the survival of decentralized and democratic governments. Former Soviet republics targeted by high levels of threat have reverted to or maintained centralized, autocratic forms of government.

Nitrate reductases and hemoglobins control nitrogen-fixing symbiosis by regulating nitric oxide accumulation

2020 ◽  
Author(s):  
Antoine Berger ◽  
Alexandre Boscari ◽  
Alain Puppo ◽  
Renaud Brouquisse
Keyword(s):  
Nitric Oxide ◽  
Defense Responses ◽  
Nodule Formation ◽  
No Production ◽  
Degradation Pathways ◽  
Atmospheric Nitrogen ◽  
Metabolic Intermediate ◽  
Hypoxic Environment ◽  
Nitrate Reductases

Abstract The interaction between legumes and rhizobia leads to the establishment of a symbiotic relationship between plant and bacteria. This is characterized by the formation of a new organ, the nodule, which facilitates the fixation of atmospheric nitrogen (N2) by nitrogenase through the creation of a hypoxic environment. Nitric oxide (NO) accumulates at each stage of the symbiotic process. NO is involved in defense responses, nodule organogenesis and development, nitrogen fixation metabolism, and senescence induction. During symbiosis, either successively or simultaneously, NO regulates gene expression, modulates enzyme activities, and acts as a metabolic intermediate in energy regeneration processes via phytoglobin-NO respiration and the bacterial denitrification pathway. Due to the transition from normoxia to hypoxia during nodule formation, and the progressive presence of the bacterial partner in the growing nodules, NO production and degradation pathways change during the symbiotic process. This review analyzes the different source and degradation pathways of NO, and highlights the role of nitrate reductases and hemoproteins of both the plant and bacterial partners in the control of NO accumulation.

scholarly journals A Model Study on the Role of Wetland Zones in Lake Eutrophication and Restoration

2001 ◽  
Vol 1 ◽  
pp. 605-614 ◽  
Author(s):  
J.H. Janse ◽  
W. Ligtvoet ◽  
S. Van Tol ◽  
A.H.M. Bresser
Keyword(s):  
Nutrient Loading ◽  
Predatory Fish ◽  
Nutrient Concentrations ◽  
Fish Stock ◽  
Mixing Rate ◽  
Marsh Vegetation ◽  
Model Calculations ◽  
Critical Loading ◽  
Marsh Area

Shallow lakes respond in different ways to changes in nutrient loading (nitrogen, phosphorus). These lakes may be in two different states: turbid, dominated by phytoplankton, and clear, dominated by submerged macrophytes. Both states are self-stabilizing; a shift from turbid to clear occurs at much lower nutrient loading than a shift in the opposite direction. These critical loading levels vary among lakes and are dependent on morphological, biological, and lake management factors. This paper focuses on the role of wetland zones. Several processes are important: transport and settling of suspended solids, denitrification, nutrient uptake by marsh vegetation (increasing nutrient retention), and improvement of habitat conditions for predatory fish. A conceptual model of a lake with surrounding reed marsh was made, including these relations. The lake-part of this model consists of an existing lake model named PCLake[1]. The relative area of lake and marsh can be varied. Model calculations revealed that nutrient concentrations are lowered by the presence of a marsh area, and that the critical loading level for a shift to clear water is increased. This happens only if the mixing rate of the lake and marsh water is adequate. In general, the relative marsh area should be quite large in order to have a substantial effect. Export of nutrients can be enhanced by harvesting of reed vegetation. Optimal predatory fish stock contributes to water quality improvement, but only if combined with favourable loading and physical conditions. Within limits, the presence of a wetland zone around lakes may thus increase the ability of lakes to cope with nutrients and enhance restoration. Validation of the conclusions in real lakes is recommended, a task hampered by the fact that, in the Netherlands, many wetland zones have disappeared in the past.

The Role of Deterrence in a new European strategic environment

2018 ◽  
Vol 2 (1) ◽  
pp. 1-15
Author(s):  
Rob de Wijk
Keyword(s):  
Cold War ◽  
Theoretical Foundation ◽  
Security Strategy ◽  
The Crimea ◽  
Russian Military ◽  
The Baltic ◽  
The Cold War ◽  
Complete Overhaul ◽  
Crimea Peninsula

Abstract: The new Russian military doctrine from 2010, the growing international assertiveness of Russia, and eventually the annexation of the Crimea Peninsula in 2014 have forced the West to rethink deterrence strategies vis a vis Russia. Consequently, the old Cold War concept of deterrence was dusted off and the debate picked up from where it had ended in 1990. This article summarizes the end of the Cold War thinking on deterring aggression against NATO-Europe. It explains why the present Western theoretical foundation of deterrence, which still focuses on strong conventional forces backed up by nuclear weapons, no longer suffices, and argues that the new Russian concept of strategic deterrence requires a complete overhaul of the Western approach. It is not only the security of the Baltic member states of NATO or of transatlantic cables that matter, Europe has to cope with desinformation and destabilization campaigns and has to rethink its energy security strategy. Only together can NATO and EU master these challenges.

Sign in / Sign up

Export Citation Format

Share Document