Search results for "Rust"
showing 10 items of 1659 documents
Age and tectonic setting of granitoid gneisses in the Eastern Desert of Egypt and south-west Sinai
1994
Strongly deformed and locally migmatized gneisses occur at several places in the southern Eastern Desert of Egypt and in Sinai and have variously been interpreted as a basement to Pan-african (≈900 to 600 Ma) supracrustal and intrusive assemblages. A suite of grabbroic to granitic gneisses was investigated in the Hafafit area, which constitutes an I-type calc-alkaline intrusive assemblage whose chemistry suggests emplacement along an active continental margin and whose granitoid members can be correlated with the so-called ‘Older Granites’ of Egypt. 207Pb/206Pb single zircon evaporation from three samples of the Hafafit gneisses yielded protolith emplacement ages between 677 ± 9 and 700 ± 1…
Geochemical data and zircon ages for rocks in a high-pressure belt of Chu-Yili Mountains, southern Kazakhstan: Implications for the earliest stages o…
2011
Abstract The mechanism and age of Palaeozoic accretion in the Central Asian Orogenic Belt remain poorly constrained. One of the most complex belts extends from the Kokchetav area in northern Kazakhstan to the Kyrgyz northern Tianshan. It represents an assemblage of small blocks with Palaeoproterozoic continental crust, intervening slivers containing early Palaeozoic ophiolites and/or deep-marine sediments, and a number of HP and UHP metamorphic complexes. The HP–LT metamorphic rocks provide important clues for reconstructions of the overall structure and evolution of the accretionary collage. This study is aimed to constrain the metamorphic age and tectonic implications of HP garnet pyroxen…
Micro-investment perspective and the potential of the universal basic income
2018
In this article, we explore the prospects of Basic Income (BI) as a development policy tool. Our approach is to analyse the BI as a tool for promoting micro-investments and as a general development policy instrument, thus deliberately departing from the perception of cash transfers as targeted poverty reduction tools. As experiences in testing BI systems in developing country contexts are limited to local and regional experiments in Namibia and India (Haarmann et al., 2009; Haarmann & Haarmann, 2012; Davala et al., 2015), conclusive assessments about the impacts of the BI cannot be drawn. Therefore, we aim to estimate potential impacts of the BI by synthesising existing knowledge. This esti…
Lever Press Duration as a Measure of Frustration Motivated Response Variation in Rat Self-administration to Investigate the Effects of Frustration on…
2023
In human studies, frustration has been identified as a potential risk factor for substance use disorders. Currently, there is little research into the role of frustration in substance use disorders despite research showing that frustration tolerance in humans is associated with a lower likelihood of developing substance use problems, better outcomes in recovery, and fewer relapses. To address this need, our studies use rat self-administration models to focus on frustration-related behavior in natural reward and addiction-related behavioral procedures. First, to study frustration in operant responding, there is a need to establish a real-time objective measure and validate its use in predict…
Big Data and Antitrust Enforcement
2017
The interaction between information, innovation and market outcomes is shaping the modern digital industries of the 21st century: the business models of search engines, social networks, e-commerce websites and marketplaces are highly reliant on the ability to gather and process large amount of data. At the same time, it is increasingly recognized that the use of Big Data by online platforms and intermediaries has far-reaching consequences not only on economic activity, but also on social and political mechanisms: technological developments affecting information flows affect the organization of markets as well as the nature of individual interactions and the functioning of the political proc…
Compartmentalization of gypsum and halite associated with cyanobacteria in saline soil crusts
2016
The interface between biological and geochemical components in surface crust of a saline soil was investigated using X-Ray Diffraction (XRD), and variable pressure scanning electron microscopy (SEM) in combination with Energy Dispersive X-ray Spectrometry (EDS). Mineral compounds such as halite and gypsum were identified crystallized around filaments of cyanobacteria. A total of 92 genera were identified from the bacterial community based on 16S gene pyrosequencing analysis. The occurrence of the gypsum crystals, their shapes and compartmentalization suggested that they separated NaCl from the immediate microenvironment of the cyanobacteria, and that some cyanobacteria and communities of su…
Phosphorylation of serine residues is fundamental for the calcium-binding ability of Orchestin, a soluble matrix protein from crustacean calcium stor…
2003
International audience; Orchestia cavimana is a terrestrial crustacean, which cyclically stores calcium in diverticula of the midgut, in the form of calcified amorphous concretions. These concretions are associated with a proteinaceous matrix, the main constituent of the soluble matrix is Orchestin, an acidic calcium-binding protein [Testenière et al., Biochem. J. 361 (2002) 327-335]. In the present paper, we clearly demonstrate that Orchestin is phosphorylated on serine and tyrosine residues, but that calcium binding only occurs via the phosphoserine residues. To our knowledge, this is the first example of an invertebrate mineralization for which a post-translational modification is clearl…
The effects of reward and frustration in patients with bipolar disorder: Evidence from a computerized task with non-contingent feedback.
2021
Abstract Background: Bipolar disorder (BD) is characterized by mood changes that implies alterations in reward sensitivity and frustration tolerance. This study examined the effects of monetary reward and frustration on attentional performance and on affective experience across mood states in BD. Methods: An Affective Posner Task in which the nature of contingencies are divided in the three successive blocks (baseline condition, monetary reward and non-contingent feedback) was applied to BD individuals in their different episodes: mania (n = 30), depression (n = 30), and euthymia (n = 30) as well as to a group of healthy controls (n = 30). Results: Monetary reward improved performance (in …
Environmental impact on historical monuments: The black crusts of the Venice lagoon
2020
Black crusts are typical decay forms on calcareous rocks in polluted urban environments. Their origin is due to “sulphation” reaction of calcium carbonate substrates (CaCO3), as a consequence of pH value decrease caused by SO2 in the polluted atmosphere. They can be therefore defined as a passive air pollution sampler. For the purpose of this work, samples from the historic center of Venice were analyzed. The city of Venice suffers in particular maritime and industrial pollution (Marghera industrial zone). By means of minero-petrographic and geochemical analyses, it was possible to obtain information on the mineralogy of the crust and its interaction with the underlying substrates, other th…
Emergence of blueschists on Earth linked to secular changes in oceanic crust composition
2015
The oldest blueschists—metamorphic rocks formed during subduction—are of Neoproterozoic age1, and 0.7–0.8 billion years old. Yet, subduction of oceanic crust to mantle depths is thought to have occurred since the Hadean, over 4 billion years ago2. Blueschists typically form under cold geothermal gradients of less than 400 °C GPa−1, so their absence in the ancient rock record is typically attributed to hotter pre-Neoproterozoic mantle prohibiting such low-temperature metamorphism; however, modern analogues of Archaean subduction suggest that blueschist-facies metamorphic conditions are attainable at the slab surface3. Here we show that the absence of blueschists in the ancient geological rec…