3,123 research outputs found

    Subjective Causality and Counterfactuals in the Social Sciences

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    The article explores the role that subjective evidence of causality and associated counterfactuals and counterpotentials might play in the social sciences where comparative cases are scarce. This scarcity rules out statistical inference based upon frequencies and usually invites in-depth ethnographic studies. Thus, if causality is to be preserved in such situations, a conception of ethnographic causal inference is required. Ethnographic causality inverts the standard statistical concept of causal explanation in observational studies, whereby comparison and generalization, across a sample of cases, are both necessary prerequisites for any causal inference. Ethnographic causality allows, in contrast, for causal explanation prior to any subsequent comparison or generalization

    Quantifying transport into the lowermost stratosphere using simultaneous in-situ measurements of SF6 and CO2

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    The seasonality of transport and mixing of air into the lowermost stratosphere (LMS) is studied using distributions of mean age of air and a~mass balance approach, based on in-situ observations of SF6 and CO2 during the SPURT (Spurenstofftransport in der Tropopausenregion, trace gas transport in the tropopause region) aircraft campaigns. Combining the information of the mean age of air and the water vapour distributions we demonstrate that the tropospheric air transported into the LMS above the extratropical tropopause layer (ExTL) originates predominantly from the tropical tropopause layer (TTL). The concept of our mass balance is based on simultaneous measurements of the two passive tracers and the assumption that transport into the LMS can be described by age spectra which are superposition of two different modes. Based on this concept we conclude that the stratospheric influence on LMS composition is strongest in April with tropospheric fractions (Îą1) below 20% and that the strongest tropospheric signatures are found in October with (Îą1 greater than 80%. Beyond the fractions, our mass balance concept allows to calculate the associated transit times for transport of tropospheric air from the tropics into the LMS. The shortest transit times (<0.3 years) are derived for the summer, continuously increasing up to 0.8 years by the end of spring. These findings suggest that strong quasi-horizontal mixing across the weak subtropical jet from summer to mid of autumn and the considerably shorter residual transport time-scales within the lower branch of the Brewer-Dobson circulation in summer than in winter dominates the tropospheric influence in the LMS until the beginning of next year's summer

    Quantifying transport into the lowermost stratosphere using simultaneous in-situ measurements of SF6 and CO2

    Get PDF
    The seasonality of transport and mixing of air into the lowermost stratosphere (LMS) is studied using distributions of mean age of air and a mass balance approach, based on in-situ observations of SF6 and CO2 during the SPURT (Spurenstofftransport in der Tropopausenregion, trace gas transport in the tropopause region) aircraft campaigns. Combining the information of the mean age of air and the water vapour distributions we demonstrate that the tropospheric air transported into the LMS above the extratropical tropopause layer (ExTL) originates predominantly from the tropical tropopause layer (TTL). The concept of our mass balance is based on simultaneous measurements of the two passive tracers and the assumption that transport into the LMS can be described by age spectra which are superposition of two different modes. Based on this concept we conclude that the stratospheric influence on LMS composition is strongest in April with extreme values of the tropospheric fractions (alpha1) below 20% and that the strongest tropospheric signatures are found in October with alpha1 greater than 80%. Beyond the fractions, our mass balance concept allows us to calculate the associated transit times for transport of tropospheric air from the tropics into the LMS. The shortest transit times (<0.3 years) are derived for the summer, continuously increasing up to 0.8 years by the end of spring. These findings suggest that strong quasi-horizontal mixing across the weak subtropical jet from summer to mid of autumn and the considerably shorter residual transport time-scales within the lower branch of the Brewer-Dobson circulation in summer than in winter dominates the tropospheric influence in the LMS until the beginning of next year's summer

    Endogenous Exchange Rate Pass-through when Nominal Prices are Set in Advance

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    This paper develops a model of endogenous exchange rate pass through within an open economy macroeconomic framework, where both pass-through and the exchange rate are simultaneously determined, and interact with one another. Pass-through is endogenous because firms choose the currency in which they set their export prices. There is a unique equilibrium rate of pass-through under the condition that exchange rate volatility rises as the degree of pass-through falls. We show that the relationship between exchange rate volatility and economic structure may be substantially affected by the presence of endogenous pass-through. Our key results show that pass-through is related to the relative stability of monetary policy. Countries with relatively low volatility of money growth will have relatively low rates of exchange rate pass-through, while countries with relatively high volatility of money growth will have relatively high pass-through rates.

    Endogenous Exchange Rate Pass-through when Nominal Prices are Set in Advance

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    This paper develops a model of endogenous exchange rate pass-through within an open economy macroeconomic framework, where both passthrough and the exchange rate are simultaneously determined, and interact with one another. Pass-through is endogenous because firms choose the currency in which they set their export prices. There is a unique equilibrium rate of pass-through under the condition that exchange rate volatility rises as the degree of pass-through falls. We show that the relationship between exchange rate volatility and economic structure may be substantially affected by the presence of endogenous pass-through. Our key results show that pass-through is related to the relative stability of monetary policy. Countries with relatively low volatility of money growth will have relatively low rates of exchange rate pass-through, while countries with relatively high volatility of money growth will have relatively high pass-through rates.

    Paper Session III-B - Computerized Tomography (CT) Inspection of Mechanics of Granular Materials (MGM) Modules for the Study and Analysis of Phenomena such as Earthquakes

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    Suppose someone sawed through a thick log, gathered up all the saw dust in a bag, and gave it to you requesting that you put the saw dust particles back together just as they were in the tree. And, no fair looking at the sawed ends of the log; not that would help! If you could re-assemble the particles exactly as they were in the tree, you would have a tomo- (slice) gram (picture) of just that thin section of the log. This of course would be impossible, but in the late 1960s, a fellow (G. Hounsfield) at EMI, Ltd. In England used an established mathematical theory by J. Radon (Radon\u27s theorem) to do that task (Reference 1). Hounsfield\u27s saw was x-radiation, and the saw dust grains, gathered with a powerful computer and re-assembled exactly, are called pixels. Each saw dust grain, (pixel) is a computerized picture element representing a small (e.g. 1mm by 1mm) density region of the original object (the log). Correctly placed together, the pixels represent a density map of the object sliced. Now Hounsfield did not slice a log, but applied his Nobel Prize winning invention to the imaging of tissue, and the diagnosis of disease, in the human body. In the early days, the slices were all performed across the axis of the specimen (body) and thus was born the CAT scan acronym meaning Computed (computerized) Axial Tomography. Improvements in the way objects can be x-ray sliced (any plane) and subsequently reproduced into images have resulted in dropping the axial term, and the favored acronym is just CT

    The literature of chemoinformatics : 1978–2018

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    This article presents a study of the literature of chemoinformatics, updating and building upon an analogous bibliometric investigation that was published in 2008. Data on outputs in the field, and citations to those outputs, were obtained by means of topic searches of the Web of Science Core Collection. The searches demonstrate that chemoinformatics is by now a well-defined sub-discipline of chemistry, and one that forms an essential part of the chemical educational curriculum. There are three core journals for the subject: The Journal of Chemical Information and Modeling, the Journal of Cheminformatics, and Molecular Informatics, and, having established itself, chemoinformatics is now starting to export knowledge to disciplines outside of chemistry

    Refinement of the Crystal Structure of Synthetic Tl3AsS4

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    The crystal structure of a synthetic sulfosalt, TlsAsS4, has been refined. The crystal is orthorhombic with space group Pnma .. Four formula units are contained in a unit cell of dimensions a = 0.8893(3), b = 1.0868(5) and c = 0.9088(3) nm. The final R-value is 0.04 for 759 observed reflections. The Tl(l) has seven nearest S atoms with a mean Tl-S bond length of 0.329 nm. Tl(2) has five nearest S atoms with a mean Tl-S bond length of 0.318 nm. The Tl coordination polyhedra form a three-dimensional framework. The As atom has a tetrahedral coordination by four S atoms at a mean distance of 0.216 nm. The AsS4 tetrahedra are isolated

    Ethnographic Causality

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    This book explores the problem of causal inference when a sufficient number of comparative cases cannot be found, which would permit the application of frequency based models formulated in terms of explanatory causal generalizations
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