594 research outputs found

    Stratospheric Dynamics

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    Root canal instrumentation efficacy of non-fused and fused primary molar roots:a micro-computed tomography study

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    Purpose Pulpectomy may be indicated in restorable primary teeth exhibiting irreversible pulpitis or pulpal necrosis. The purpose of this study was to compare the cleaning and shaping efficacy of NiTi systems (Reciproc(R) Blue and MTwo(R)) with manual stainless-steel instrumentation in primary molars using micro-CT analysis. Methods Fifty-seven maxillary second primary molars were scanned using micro-CT. Teeth with three divergent roots were divided randomly (n = 15) according to instrument type (K file, MTwo (R), and Reciproc (R) Blue). Teeth with root fusion were instrumented manually as a separate group (n = 12). Pre- and post-instrumentation micro-CT images were superimposed, and the instrumentation area (IA) and procedural complications were recorded. Results No statistically significant differences in IA between file systems was observed in the non-fused teeth. The mean IA of fused roots was significantly lower than in the non-fused distobuccal (p = 0.003) and palatal (p 60%) occurred in both non-fused and fused primary teeth with fewer procedural complications observed after manual instrumentation

    Improved age estimates for key Late Quaternary European tephra horizons in the RESET lattice

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    The research project 'Response of Humans to Abrupt Environmental Transitions' (RESET) used tephra layers to tie together and synchronise the chronologies of stratigraphic records at archaeological and environmental sites. With the increasing importance of tephra as chronological markers in sedimentary sequences, both in this project and more generally, comes a requirement to have good estimates for the absolute age of these volcanic horizons. This paper summarises the chronology of the key tephra in the RESET tephra lattice in the time range 10-60 ka BP, from the existing literature, from papers produced as part of the RESET project, and reanalysis conducted for this paper. The paper outlines the chronological ap- proach taken to the dating of tephra within the RESET project, and the basis for further work, as part of the INTIMATE (INTegrating Ice core MArine and TEr- restrial records) initiative. For each of the tephra layers in the lattice, the existing literature is discussed and, where relevant date estimates updated using the latest radiocarbon calibration curves (IntCal13 and Marine13) and methods. Maps show the approximate extent of tephra finds, giving a visual indication of the coverage of the lattice in different time-periods.</p

    Power and the durability of poverty: a critical exploration of the links between culture, marginality and chronic poverty

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    A comparative framework: how broadly applicable is a 'rigorous' critical junctures framework?

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    The paper tests Hogan and Doyle's (2007, 2008) framework for examining critical junctures. This framework sought to incorporate the concept of ideational change in understanding critical junctures. Until its development, frameworks utilized in identifying critical junctures were subjective, seeking only to identify crisis, and subsequent policy changes, arguing that one invariably led to the other, as both occurred around the same time. Hogan and Doyle (2007, 2008) hypothesized ideational change as an intermediating variable in their framework, determining if, and when, a crisis leads to radical policy change. Here we test this framework on cases similar to, but different from, those employed in developing the exemplar. This will enable us determine whether the framework's relegation of ideational change to a condition of crisis holds, or, if ideational change has more importance than is ascribed to it by this framework. This will also enable us determined if the framework itself is robust, and fit for the purposes it was designed to perform — identifying the nature of policy change

    Analysis of Endocrine Disruption in Southern California Coastal Fish Using an Aquatic Multispecies Microarray

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    BackgroundEndocrine disruptors include plasticizers, pesticides, detergents, and pharmaceuticals. Turbot and other flatfish are used to characterize the presence of chemicals in the marine environment. Unfortunately, there are relatively few genes of turbot and other flatfish in GenBank, which limits the use of molecular tools such as microarrays and quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) to study disruption of endocrine responses in sentinel fish captured by regulatory agencies.ObjectivesWe fabricated a multigene cross-species microarray as a diagnostic tool to screen the effects of environmental chemicals in fish, for which there is minimal genomic information. The array included genes that are involved in the actions of adrenal and sex steroids, thyroid hormone, and xenobiotic responses. This microarray will provide a sensitive tool for screening for the presence of chemicals with adverse effects on endocrine responses in coastal fish species.MethodsWe used a custom multispecies microarray to study gene expression in wild hornyhead turbot (Pleuronichthys verticalis) collected from polluted and clean coastal waters and in laboratory male zebrafish (Danio rerio) after exposure to estradiol and 4-nonylphenol. We measured gene-specific expression in turbot liver by qRT-PCR and correlated it to microarray data.ResultsMicroarray and qRT-PCR analyses of livers from turbot collected from polluted areas revealed altered gene expression profiles compared with those from nonaffected areas.ConclusionsThe agreement between the array data and qRT-PCR analyses validates this multispecies microarray. The microarray measurement of gene expression in zebrafish, which are phylogenetically distant from turbot, indicates that this multispecies microarray will be useful for measuring endocrine responses in other fish

    Where are the Pots and Pans? Collective Responses in Ireland to Neoliberalization in a Time of Crisis: Learning from Latin America

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    Since 2008, Ireland has experienced a profound multi-faceted crisis, stemming from the collapse of the financial and property sectors. Despite enduring six years of neoliberal austerity measures in response to this situation, popular protest has been muted. Using Silva's [(2009) Challenging Neoliberalism in Latin America (Cambridge and New York: Cambridge University Press)] framework of analysis of popular responses in Latin America to that region's debt crisis of the 1980s and 1990s, this article seeks to investigate why this has been the case. We assess how the crisis is being framed among popular and civil society groups, and whether increased associational and collective power is developing. In doing so, we look at processes of intra-group cooperation, cross-group cooperation and framing and brokerage mechanisms. We then ask, where such processes exist, if they can lead to a comprehensive challenge to the neoliberal policies currently being implemented, as happened in much of Latin America. We conclude that the crisis has not yet reached sufficient depth or longevity to foster a more robust popular response, but propose that analysis of similar processes in Latin America can help us understand better why this is the case, not just in Ireland, but in other countries of Europe experiencing similar situations
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