355 research outputs found
Quantifying the impact of riverine particulate dissolution in seawater on ocean chemistry
No full textThe quantification of the sources and sinks of elements to the oceans forms the basis of our understanding of global geochemical cycles and the chemical evolution of the Earth's surface. There is, however, a large imbalance in the current best estimates of the global fluxes to the oceans for many elements. In the case of strontium (Sr), balancing the input from rivers would require a much greater mantle-derived component than is possible from hydrothermal water flux estimates at mid-ocean ridges. Current estimates of riverine fluxes are based entirely on measurements of dissolved metal concentrations, and neglect the impact of riverine particulate dissolution in seawater. Here we present 87Sr/86Sr isotope data from an Icelandic estuary, which demonstrate rapid Sr release from the riverine particulates. We calculate that this Sr release is 1.1–7.5 times greater than the corresponding dissolved riverine flux. If such behaviour is typical of volcanic particulates worldwide, this release could account for 6–45% of the perceived marine Sr budget imbalance, with continued element release over longer timescales further reducing the deficit. Similar release from particulate material will greatly affect the marine budgets of many other elements, changing our understanding of coastal productivity, and anthropogenic effects such as soil erosion and the damming of rivers
Riverine particulate material dissolution as a significant flux of strontium to the oceans
No full textISI Document Delivery No.: 078DQ Times Cited: 2 Cited Reference Count: 62 Cited References: ALBAREDE F, 1981, EARTH PLANET SC LETT, V55, P229, DOI 10.1016/0012-821X(81)90102-3 Allegre CJ, 2010, EARTH PLANET SC LETT, V292, P51, DOI 10.1016/j.epsl.2010.01.019 Aller R.C, 2008, J GEOPHYS RES, P113 Aller RC, 1998, MAR CHEM, V61, P143, DOI 10.1016/S0304-4203(98)00024-3 Arsouze T., 2009, BIOGEOSCIENCES, V6, P1 BERNER RA, 1992, GEOCHIM COSMOCHIM AC, V56, P3225, DOI 10.1016/0016-7037(92)90300-8 BLUTH GJS, 1994, GEOCHIM COSMOCHIM AC, V58, P2341, DOI 10.1016/0016-7037(94)90015-9 Brass G, 1976, GEOCHIM COSMOCHIM AC, V40, P720 Broecker W. 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Pearce, Christopher R. Jeandel, Catherine Gislason, Sigurour R. Eiriksdottir, Eydis S. Mavromatis, Vasileios Oelkers, Eric H. Pearce, Christopher/A-5599-2010 Pearce, Christopher/0000-0002-4382-2341 EC Marie Curie 'MIN-GRO' Research and Training Network [MRTN-CT-2006-035488]; Marie Curie Intra-European Fellowship [PIEF-GA-2009-254495] We thank Jerome Gaillardet and John Compton for the provision of samples. Derek Vance and an anonymous reviewer provided constructive and insightful comments and criticisms on this manuscript. M. T. Jones and C. R. Pearce were supported by the EC Marie Curie 'MIN-GRO' Research and Training Network (MRTN-CT-2006-035488). M. T. Jones is currently supported by a Marie Curie Intra-European Fellowship (PIEF-GA-2009-254495). 2 ELSEVIER SCIENCE BV AMSTERDAM EARTH PLANET SC LETTThe ratio of strontium isotopes, Sr-87/Sr-86, in seawater is homogenous at any given time, yet varies considerably throughout the geological record. This variation is thought to stem from changes in the balance of predominantly radiogenic Sr entering the oceans via dissolved riverine transport, and unradiogenic Sr sourced from mid-ocean ridge hydrothermal activity. Recent evidence suggests, however, that hydrothermal exchange at mid-ocean ridges is a factor of 3 too low to balance Sr added to the oceans from dissolved continental riverine fluxes. Here we present evidence that the arrival and subsequent dissolution of riverine particulate material in seawater is a significant contributor of both radiogenic and unradiogenic Sr to the oceans. Batch experiments demonstrate that between 0.15% and 27.36% of Sr is liberated from riverine particulates to seawater within 6 months. The rates of release are dependent on surface area and particulate composition, with volcanic riverine material more reactive than continental riverine particulates. The observed rapid Sr release rate from riverine particulate material has important consequences for both chemical and isotopic mass balances in the ocean and the application of the Sr-87/Sr-86 weathering proxy to the geological record. The dissolution of riverine particulate material is likely, based on these findings, to at least partially account for the imbalance between Sr sources to the oceans. (C) 2012 Elsevier B.V. All rights reserved
Adaptive learning and macroeconomic policy in DSGE models
No full textThe Global Financial Crisis of 2007-08 highlighted the shortcomings of standard macroeconomic models within the Rational Expectations framework, commonly used at central banks for forecasting and policy analysis. The goal of this thesis is to introduce alternative models of expectation formation mechanisms to improve the performance of operational macro models, and to give new insights into monetary and fiscal policy. A special emphasis is put on the estimation of adaptive learning and heterogeneous expectations models, with the aim of increasing their empirical relevance and popularity among central banks. The research in this thesis urges policymakers to expand their macroeconomic policy toolkit with alternative forms of bounded rationality to improve the robustness and resilience of macro models, in particular during times of turmoil and increased uncertainty
Theofanis Mavromatis (Fan Noli): consequences of the nationalistic tendencies to the transmutation of national consiousness and religion
No full textTheofanis Stylianos Noli (Mavromatis) was an Albanian-American writer, scholar,diplomat, politician, orator, and founder of the Albanian Orthodox Church and isconsidered one of the most powerful political personalities of Albania. He was theinspirer and the leading spirit of the Albanian idea and its promotion to other countries.He hated Greece and the Greeks, although he was both an orthodox and a Greekhimself; the failure of the greek issue in Northern Epirus is accredited to his ownmanoeuvres.He played a leading role in the foundation and formation of the Albanian State.At the same time he fought for the separation of the Orthodox Church of Albaniafrom the Ecumenical Patriarchate. He took advantage of his atypical ordination by theRussian bishop of Alaska in order to spread his ideas. He acquired his education atHarvard and was ordained priest in 1908, establishing thereby the Albanian Churchand elevating the Albanian language to ecclesiastic use.He was the offi cial Albanian representative during the negotiations for the foundationand the borders setting of the Albanian State. He also took part in the Albaniannational assembly for the Albanian constitution (Veratio 1920). He served as ministerof Foreign Aff airs but he opposed to the ideas of Muslim Achmet Zogou. His recognitionby the Ecumenical Patriarchate gave him greater infl uence over the Christianelement, and he managed to lead a coup d’etat against Zogou administration takingover as Prime Minister (1924-1925). He was later overturned by Zogou but hefl ed to the USA, having though lost his glory as a nationalist leader. He played animportant role in the consolidation of Demotic Greek as the national language ofGreece with numerous translations of world literature masterpieces. His contributionto the English-language literature are also manifold: as a scholar and author ofa series of publications on Scanderbeg, Shakespeare, Beethoven, religious texts andtranslations. Among his most important works one can fi nd: The story of Skanderbeg(1921), My life in Albania (1931), Byzantine Hymnologion (1951), Beethoven and theFrench revolution (1947) etc. Until his death (1965) he dedicated himself to writingHistory and Litterature. His struggle and his work as a writer share one commoncharacteristic, his intense religious spirit. This characteristic restricted his exceptionalpersonal abilities leading him to frivolous choices which were both unambiguous andcontroversial with extremely painful consequences regarding the cohesiveness of theAlbanian Christian element itself.The Orthodox Church of Albania has suff ered a great deal from nationalists andcommunists. Even today, in Albania, there exist political and religious (Islamic) forceswhich struggle against Hellenism and Christianism. It is our duty to protect our nation(Greece), as well as our political and religious tradition. The Church will have to helppreserve our legacy but at the same time to try to convince people that pure love iswhat human relationships should be based on
Hypnagogia: The nature and function of the hypnagogic state
No full textThis thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.An analysis of the hypnagogic state (hypnagogia) leads to the conclusion that, far from being a simple phase of sleep, this state or process is a central phenomenon
characterized by a constellation of psychological features which emerge as a function of the hypnagogic subject's
loosening of ego boundaries (LEB) and are correlated with activities of subcortical structures. This analysis both facilitates the relating of hypnagogia to other states/
processes of the human organism, such as hypnosis, meditation, dreams, psi, schizophrenia, and creativity, and
helps shed light on their nature. Further, hypnagogia is viewed as a circadian phenomenon. related to the basic restactivity
cycle wherein it represents the cycle's dream
component. As such it encompasses a variety of types of dream, the nocturnal or REM kind being only one of them. It, thus, constitutes the exemplification of a basic and pervading phenomenon herein termed Oneirosis, i.e. the need and readiness to have dreams and dreamlike experiences,
such as hallucinations and quasi-hallucinations, throughout the 24 hour cycle independently of sleep and wakefulness.
It is further proposed, on neurophysiological, developmental and psychological grounds, that this phenomenon
is evolutionally older than sleep and wakefulness, that it has a hypometabolic and anxiety-reducing function, and that, by dint of its character of LEB, it enables the
individual to slacken his ego strictness and become more tolerant as well as providing him with opportunities for more holistic experiences and continually renewed psychological orientations. Moreover, due to its unique character of riding between wakefulness and sleep, hypnagogia
points to new evolutional possibilities, namely, to the establishment of a new psychological state serving collectively
the functions of wakefulness, sleep, and dreaming.This work is funded by the Social Science Research Council (No. 79/20805/PSY
Use of drought indices in climate change impact assessment studies: an application to Greece
No full textChanges in exceptional hydrological and meteorological weekly event frequencies in Greece
No full textClimate-Cereal Crop Relationships in Greece and the Impacts of Recent Climate Trends: The Role of the Effective “Growing Season” Definition
No full textThe implications for welfare of varying degrees of capital mobility and the possibility of a non-zero optimal tariff for a small open economy in a dynamic CGE model
No full textThis thesis was scanned from the print manuscript for digital preservation and is copyright the author.
Researchers can access this thesis by asking their local university, institution or public library to
make a request on their behalf. Monash staff and postgraduate students can use the link in the References field
Comparison of climate change scenario construction methodologies for impact assessment studies
No full textThis paper explores three important aspects of studies that assess the possible effects of climatic change on agricultural productivity at regional spatial scales. First, long-term historic and stochastically generated (WGEN) weather records are compared in terms of their statistical attributes using the climate conditions found in central France. Second, our results show that the use of CERES-wheat coupled with WGEN produced weather data provides an efficient method for assessing the impacts of changing climate on average agricultural production. Less confidence can be placed, however on the estimation of future agricultural risk and variability assessment. Finally, time series of climate variables with changed mean and variability are either constructed according to the methodology proposed by Mearns et al. (1992) or simulated with WGEN using the approach suggested by Riha et al. (1996). The climate change scenarios are compared in terms of their effects on wheat development and predicted yield with CERES-wheat using dally data from the sulphate integration of the HadCM2 General Circulation Model to drive the crop model. The comparison of the different approaches for the construction of climate change scenario demonstrates the relative importance of changes in the mean climate and short/long-term variability in the prediction of crop yield on a regional basis. The results also indicate that the strength of the yield response to such combined scenarios and sometimes even its sign, depends on the qualitative nature of the change. Therefore, assessments of future agricultural productivity based on this methodological approach must be regarded as speculative reserved
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