Genesis and evolution of mafic microgranular enclaves through various types of interaction between coexisting felsic and mafic magmas

1992 ◽  
Vol 83 (1-2) ◽  
pp. 145-153 ◽  
Author(s):  
Bernard Barbarin ◽  
Jean Didier
Keyword(s):  
Chemical Exchange ◽  
Magma Chambers ◽  
Mixing Processes ◽  
Microgranular Enclaves ◽  
Mafic Microgranular Enclaves ◽  
Mass Fractions ◽  
Long Time ◽  
Mafic Magmas ◽  
The Many ◽  
Structural Levels

ABSTRACTThermal, mechanical and chemical exchange occurs between felsic and mafic magmas in dynamic magma systems. The occurrence and efficiency of such exchanges are constrained mainly by the intensive parameters, the compositions, and the mass fractions of the coexisting magmas. As these interacting parameters do not change simultaneously during the evolution of the granite systems, the exchanges appear sequentially, and affect magmatic systems at different structural levels, i.e. in magma chambers at depth, in the conduits, or after emplacement. Hybridisation processes are especially effective in the plutonic environment because contrasting magmas can interact over a long time-span before cooling. The different exchanges are complementary and tend to reduce the contrasts between the coexisting magmas. They can be extensive or limited in space and time; they are either combined into mixing processes which produce homogeneous rocks, or only into mingling processes which produce rocks with heterogeneities of various size-scales. Mafic microgranular enclaves represent the most common heterogeneities present in the granite plutons. The composite enclaves and the many types of mafic microgranular enclaves commonly associated in a single pluton, or in polygenic enclave swarms, are produced by the sequential occurrence of various exchanges between coexisting magmas with constantly changing intensive parameters and mass fractions. The complex succession and repetition of exchanges, and the resulting partial chemical and complete isotopic equilibration, mask the original identities of the initial components.

Review about structure and evaluation of reactivators of Acetylcholinesterase inhibited with neurotoxic organophosphorus compounds

2020 ◽  
Vol 27 ◽  
Author(s):  
José Daniel Figueroa-Villar ◽  
Elaine C. Petronilho ◽  
Kamil Kuca ◽  
Tanos C. C. Franca
Keyword(s):  
Organophosphorus Compounds ◽  
Chemical Warfare Agents ◽  
Nerve Impulse ◽  
Limited Capacity ◽  
New Agents ◽  
Long Time ◽  
Warfare Agents ◽  
Comprehensive Search ◽  
Pharmacology And Toxicology ◽  
The Many

Background: Neurotoxic chemical warfare agents can be classified as some of the most dangerous chemicals for humanity. The most effective of those agents are the organophosphates (OPs) capable of restricting the enzyme acetylcholinesterase (AChE), which in turn controls the nerve impulse transmission. When AChE is inhibited by OPs, its reactivation can be usually performed through cationic oximes. However, until today it has not been developed one universal defense agent, with complete effective reactivation activity for AChE inhibited by any of the many types of existing neurotoxic OPs. For this reason, before treating people intoxicated by an OP, it is necessary to determine the neurotoxic compound that was used for contamination, in order to select the most effective oxime. Unfortunately, this task usually requires a relative long time, raising the possibility of death. Cationic oximes also display a limited capacity of permeating the blood-brain barrier (BBB). This fact compromises their capacity of reactivating AChE inside the nervous system. Methods: We performed a comprehensive search on the data about OPs available on the scientific literature today in order to cover all the main drawbacks still faced in the research for the development of effective antidotes against those compounds. Results: Therefore, this review about neurotoxic OPs and the reactivation of AChE, provides insights for the new agents’ development. The most expected defense agent is a molecule without toxicity and effective to reactivate AChE inhibited by all neurotoxic OPs. Conclusion: To develop these new agents it is necessary the application of diverse scientific areas of research, especially theoretical procedures as computational science (computer simulation, docking and dynamics); organic synthesis; spectroscopic methodologies; biology, biochemical and biophysical information; medicinal chemistry, pharmacology and toxicology.

The Many Faces of Socioeconomic Change

2017 ◽  
Author(s):  
John Toye
Keyword(s):  
Socioeconomic Development ◽  
Adam Smith ◽  
First Century ◽  
Social Progress ◽  
Long Time ◽  
The Face ◽  
Scientific Expertise ◽  
The Many ◽  
Century Development

This book provides a survey of different ways in which economic sociocultural and political aspects of human progress have been studied since the time of Adam Smith. Inevitably, over such a long time span, it has been necessary to concentrate on highlighting the most significant contributions, rather than attempting an exhaustive treatment. The aim has been to bring into focus an outline of the main long-term changes in the way that socioeconomic development has been envisaged. The argument presented is that the idea of socioeconomic development emerged with the creation of grand evolutionary sequences of social progress that were the products of Enlightenment and mid-Victorian thinkers. By the middle of the twentieth century, when interest in the accelerating development gave the topic a new impetus, its scope narrowed to a set of economically based strategies. After 1960, however, faith in such strategies began to wane, in the face of indifferent results and general faltering of confidence in economists’ boasts of scientific expertise. In the twenty-first century, development research is being pursued using a research method that generates disconnected results. As a result, it seems unlikely that any grand narrative will be created in the future and that neo-liberalism will be the last of this particular kind of socioeconomic theory.

At Nature's Edge

2018 ◽  
Keyword(s):  
Human Impacts ◽  
Military Bases ◽  
East African ◽  
African Countries ◽  
The Road ◽  
European Experience ◽  
The Everyday ◽  
Long Time ◽  
The Indian Ocean ◽  
The Many

In an epoch when environmental issues make the headlines, this is a work that goes beyond the everyday. Ecologies as diverse as the Himalayas and the Indian Ocean coast, the Negev desert and the former military bases of Vietnam, or the Namib desert and the east African savannah all have in common a long-time human presence and the many ways people have modified nature. With research in six Asian and African countries, the authors come together to ask how and why human impacts on nature have grown in scale and pace from a long pre-history. The chapters in this volume illumine specific patterns and responses across time, going beyond an overt centring of the European experience. The tapestry of life and the human reshaping of environments evoke both concern and hope, making it vital to understand when, why, and how we came to this particular turn in the road. Eschewing easy labels and questioning eurocentrism in today’s climate vocabulary, this is a volume that will stimulate rethinking among scholars and citizens alike.

scholarly journals Applying the SDGs to Cities: Business as Usual or a New Dawn?

2018 ◽  
Vol 10 (9) ◽  
pp. 3201 ◽  
Author(s):  
Roland Zinkernagel ◽  
James Evans ◽  
Lena Neij
Keyword(s):  
Environmental Sustainability ◽  
Integrated Approach ◽  
Sustainable Urban Development ◽  
Long Time ◽  
Development Goals ◽  
Urban Contexts ◽  
The Many ◽  
Business As Usual ◽  
The City ◽  
Indicator Sets

With growing urbanisation the sustainability of cities has become increasingly important. Although cities have been using indicators for a long time it is only in the last decades that attempts have been made to collate indicators into sets that reflect the many different aspects required to assess the sustainability of a city. The aim of this paper is to review the evolution of indicators for monitoring sustainable urban development in order to understand how ‘new’ the indicators suggested by the UN Sustainable Development Goals (SDGs) are for cities and the challenges they may face in using them. The review reveals that previous indicator sets emphasised environmental sustainability, health and economic growth. It is also shown that indicator sets that pre-date the SDGs lacked dimensions such as gender equality and reduced inequalities. In all, the SDG indicators provide the possibility of a more balanced and integrated approach to urban sustainability monitoring. At the same time, further research is needed to understand how to adapt the SDGs, targets and indicators to specific urban contexts. Challenges of local application include their large number, their generic characteristics and the need to complement them with specific indicators that are more relevant at the city level.

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