180 research outputs found

    The measurement of social stratification : comparative perspectives between Europe and Latin America

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    Production of INCASI Project H2020-MSCA-RISE-2015 GA 691004This chapter analyses compared social stratification in three Latin American countries (Argentina, Chile and Uruguay) and four European countries (Finland, France, Spain, Great Britain). We focus on both external and internal borders of social classes, as well as on the challenges posed by their analysis for sociology. We compare social classes using EGP6 in relation to a variety of social indicators, to examine how social classes vary among countries. We include debates on production models and welfare state policies to understand the specific configurations and compare the conditions of some of the INCASI countries regarding social stratification. Lastly, we apply a latent class analysis to validate the number of social classes and to recognise class boundaries

    Social mobility from a comparative perspective between Europe and Latin America

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    Production of INCASI Project H2020-MSCA-RISE-2015 GA 691004This chapter presents a review of the analysis of social mobility in the international sphere (Europe and Latin America), with a particular focus on the partner countries of the INCASI network. To date, few studies have linked nations whose economic and social aspects are so dissimilar. As is usual in the specialized literature, the relationship between social origin and class destination is addressed. This is done by noting the comparisons made across the geographical areas. We review the analyses that have been made of the evolution of social fluidity as well as the distance between social classes within each country and the comparisons made between them. We compare the main theories that have inspired the study of social mobility to date: modernization theory, which predicts an increase in relative mobility rates, and invariance theory, which postulates the constancy of social fluidity. Special attention is devoted to the role played by the family, the state and the market in late industrialized countries. We study the difficulties for social change, i.e. upward mobility from one class to another, as well as the likelihood of reproduction in comparative terms. To do so, we link these mechanisms with the AMOSIT model. The advances in methodology, techniques, theory and data processing are highlighted

    Alteration assemblages in Martian meteorites: implications for near-surface processes

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    The SNC (Shergotty-Nakhla-Chassigny) meteorites have recorded interactions between martian crustal fluids and the parent igneous rocks. The resultant secondary minerals – which comprise up to 1 vol.% of the meteorites – provide information about the timing and nature of hydrous activity and atmospheric processes on Mars. We suggest that the most plausible models for secondary mineral formation involve the evaporation of low temperature (25 – 150 °C) brines. This is consistent with the simple mineralogy of these assemblages – Fe-Mg-Ca carbonates, anhydrite, gypsum, halite, clays – and the chemical fractionation of Ca-to Mg-rich carbonate in ALH84001 "rosettes". Longer-lived, and higher temperature, hydrothermal systems would have caused more silicate alteration than is seen and probably more complex mineral assemblages. Experimental and phase equilibria data on carbonate compositions similar to those present in the SNCs imply low temperatures of formation with cooling taking place over a short period of time (e.g. days). The ALH84001 carbonate also probably shows the effects of partial vapourisation and dehydration related to an impact event post-dating the initial precipitation. This shock event may have led to the formation of sulphide and some magnetite in the Fe-rich outer parts of the rosettes. Radiometric dating (K-Ar, Rb-Sr) of the secondary mineral assemblages in one of the nakhlites (Lafayette) suggests that they formed between 0 and 670 Myr, and certainly long after the crystallisation of the host igneous rocks. Crystallisation of ALH84001 carbonate took place 0.5 Gyr after the parent rock. These age ranges and the other research on these assemblages suggest that environmental conditions conducive to near-surface liquid water have been present on Mars periodically over the last 1 Gyr. This fluid activity cannot have been continuous over geological time because in that case much more silicate alteration would have taken place in the meteorite parent rocks and the soluble salts would probably not have been preserved. The secondary minerals could have been precipitated from brines with seawater-like composition, high bicarbonate contents and a weakly acidic nature. The co-existence of siderite (Fe-carbonate) and clays in the nakhlites suggests that the pCO2 level in equilibrium with the parent brine may have been 50 mbar or more. The brines could have originated as flood waters which percolated through the top few hundred meters of the crust, releasing cations from the surrounding parent rocks. The high sulphur and chlorine concentrations of the martian soil have most likely resulted from aeolian redistribution of such aqueously-deposited salts and from reaction of the martian surface with volcanic acid volatiles. The volume of carbonates in meteorites provides a minimum crustal abundance and is equivalent to 50–250 mbar of CO2 being trapped in the uppermost 200–1000 m of the martian crust. Large fractionations in 18O between igneous silicate in the meteorites and the secondary minerals (30) require formation of the latter below temperatures at which silicate-carbonate equilibration could have taken place (400°C) and have been taken to suggest low temperatures (e.g. 150°C) of precipitation from a hydrous fluid

    Acute Cellular Alterations in the Hippocampus After Status Epilepticus

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    The critical, fundamental mechanisms that determine the emergence of status epilepticus from a single seizure and the prolonged duration of status epilepticus are uncertain. However, several general concepts of the pathophysiology of status epilepticus have emerged: (a) the hippocampus is consistently activated during status epilepticus; (b) loss of GABA-mediated inhibitory synaptic transmission in the hippocampus is critical for emergence of status epilepticus; and, finally (c) glutamatergic excitatory synaptic transmission is important in sustaining status epilepticus. This review focuses on the alteration of GABAergic inhibition in the hippocampus that occurs during the prolonged seizures of status epilepticus. If reduction in GABAergic inhibition leads to development of status epilepticus, enhancement of GABAergic inhibition would be expected to interrupt status epilepticus. Benzodiazepines and barbiturates are both used in the treatment of status epilepticus and both drugs enhance GABA A receptor-mediated inhibition. However, patients often become refractory to benzodiazepines when seizures are prolonged, and barbiturates are often then used for these refractory cases of status epilepticus. Recent evidence suggests the presence of multiple GABA A receptor isoforms in the hippocampus with different sensitivity to benzodiazepines but similar sensitivity to barbiturates, thus explaining why the two drug classes might have different clinical effects. In addition, rapid functional plasticity of GABA A receptors has been demonstrated to occur during status epilepticus in rats. During status epilepticus, there was a substantial reduction of diazepam potency for termination of the seizures. The loss of sensitivity of the animals to diazepam during status epilepticus was accompanied by an alteration in the functional properties of hippocampal dentate granule cell GABA A receptors. Dentate granule cell GABA A receptor currents from rats undergoing status epilepticus had reduced sensitivity to diazepam and zinc but normal sensitivity to GABA and pentobarbital. Therefore, the prolonged seizures of status epilepticus rapidly altered the functional properties of hippocampal dentate granule cell GABA A receptors, possibly explaining why benzodiazepines and barbiturates may not be equally effective during treatment of the prolonged seizures of status epilepticus. A comprehensive understanding of the cellular and molecular events leading to the development, maintenance, and cytotoxicity of status epilepticus should permit development of more effective treatment strategies and reduction in the mortality and morbidity of status epilepticus.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65664/1/j.1528-1157.1999.tb00873.x.pd

    Administrative social science data: The challenge of reproducible research

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    Powerful new social science data resources are emerging. One particularly important source is administrative data, which were originally collected for organisational purposes but often contain information that is suitable for social science research. In this paper we outline the concept of reproducible research in relation to micro-level administrative social science data. Our central claim is that a planned and organised workflow is essential for high quality research using micro-level administrative social science data. We argue that it is essential for researchers to share research code, because code sharing enables the elements of reproducible research. First, it enables results to be duplicated and therefore allows the accuracy and validity of analyses to be evaluated. Second, it facilitates further tests of the robustness of the original piece of research. Drawing on insights from computer science and other disciplines that have been engaged in e-Research we discuss and advocate the use of Git repositories to provide a useable and effective solution to research code sharing and rendering social science research using micro-level administrative data reproducible

    A review of educational attainment measures for social survey research

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    This article is a review of issues associated with measuring education and using educational measures in social science research. The review is orientated towards researchers who undertake secondary analyses of large-scale micro-level social science datasets. The article begins with an outline of important context, which impinges upon the measurement of education. The United Kingdom is the focus of this review, but similar issues apply to other nation states. We provide a critical introduction to the main approaches to measuring education in social survey research, which include measuring years of education, using categorical qualification based measures and scaling approaches. We advocate the use of established education measures to better facilitate comparability and replication. We conclude by making the recommendation that researchers place careful thought into which educational measure they select, and that researchers should routinely engage in appropriate sensitivity analyses

    Ischaemic conditioning and targeting reperfusion injury: a 30 year voyage of discovery

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    To commemorate the auspicious occasion of the 30th anniversary of IPC, leading pioneers in the field of cardioprotection gathered in Barcelona in May 2016 to review and discuss the history of IPC, its evolution to IPost and RIC, myocardial reperfusion injury as a therapeutic target, and future targets and strategies for cardioprotection. This article provides an overview of the major topics discussed at this special meeting and underscores the huge importance and impact, the discovery of IPC has made in the field of cardiovascular research

    Single-neuron dynamics in human focal epilepsy

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    Epileptic seizures are traditionally characterized as the ultimate expression of monolithic, hypersynchronous neuronal activity arising from unbalanced runaway excitation. Here we report the first examination of spike train patterns in large ensembles of single neurons during seizures in persons with epilepsy. Contrary to the traditional view, neuronal spiking activity during seizure initiation and spread was highly heterogeneous, not hypersynchronous, suggesting complex interactions among different neuronal groups even at the spatial scale of small cortical patches. In contrast to earlier stages, seizure termination is a nearly homogenous phenomenon followed by an almost complete cessation of spiking across recorded neuronal ensembles. Notably, even neurons outside the region of seizure onset showed significant changes in activity minutes before the seizure. These findings suggest a revision of current thinking about seizure mechanisms and point to the possibility of seizure prevention based on spiking activity in neocortical neurons

    A Review of occupation-based social classifications for social survey research

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    This article is a review of issues associated with measuring occupations and using occupation-based socio-economic classifications in social science research. The review is orientated towards researchers who undertake secondary analysis of large-scale micro-level social science datasets. This article begins with an outline of how to handle raw occupational information. This is followed by an introduction to the two main approaches to measuring occupations and a third lesser known but intellectually innovative approach. The three approaches are social class schemes, social stratification scales and the microclass approach. International comparisons are briefly described and a discussion of intersectionality with other key variables such as age and gender is provided. We are careful to emphasise that this article does not advocate the uncritical adoption of any one particular occupation-based socio-economic measure over and above other alternatives. Rather, we are advocating that researchers should choose from the portfolio of existing socio-economic measures in an informed and empirically defensible way, and we strongly advocate undertaking sensitivity analyses. We conclude that researchers should always use existing socio-economic measures that have agreed on and well-documented standards. We strongly advise researchers not to develop their own measures without strong justification nor to use existing measures in an un-prescribed or ad hoc manner
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