Testing the timing of radiocarbon-dated events between proxy archives

For interpreting past changes on a regional or global scale, the timings of proxy-inferred events are usually aligned with data from other locations. However, too often chronological uncertainties are ignored in proxy diagrams and multisite comparisons, making it possible for researchers to fall into the trap of sucking separate events into one illusionary event (or vice versa). Here we largely solve this "suck in and smear syndrome" for radiocarbon (14C) dated sequences. In a Bayesian framework, millions of plausible age-models are constructed to quantify the chronological uncertainties within and between proxy archives. We test the technique on replicated high-resolution 14C-dated peat cores deposited during the "Little Ice Age" (c. AD 1400-1900), a period characterized by abrupt climate changes and severe 14C calibration problems. Owing to internal variability in proxy data and uncertainties in age-models, these (and possibly many more) archives are not consistent in recording decadal climate change. Through explicit statistical tests of palaeoenvironmental hypotheses, we can move forward to systematic interpretations of proxy data. However, chronological uncertainties of non-annually resolved palaeoclimate records are too large for answering decadal timescale questions.

Out of tune: the dangers of aligning proxy archives

Tuning is a widespread technique to combine, date and interpret multiple fossil proxy archives through aligning supposedly synchronous events between the archives. The approach will be reviewed by discussing a number of literature examples, ranging from peat and tephra layers to orbital tuning and d¹⁸O series from marine and ice deposits. Potential problems will be highlighted such as the dangers of circular reasoning and unrecognised chronological uncertainties, and some solutions suggested. Fossil proxy research could become enhanced if tuning were approached in a more quantitative, reliable and objective way, and especially if individual proxy archives were non-tuned and kept on independent time-scales.

Weathering Rinds: Archives of Paleoenvironments on Mount Kenya, East Africa

Weathering-rind thicknesses on pebble-and cobble-size sediment have been used for the past half-century, at least, as an age indicator of postdepositional time following a geologic event. In mountainous terrain, rind thickness is taken as a measurement of weathering over time frames of 0.5 m.yr.; variable thicknesses are used to discriminate relative ages of glacial deposits. The effects of chemical and physical weathering that together produce rinds are only rarely considered, and most research objectives have centered on lichen alteration of clast surfaces. Recent microscopic analyses of weathering rinds on volcanic clasts of similar to 70.0-ka to similar to 2.0-m.yr. age produced new data on weathering products as well as unexpected incorporated biotic materials undergoing diagenesis. The question as to how much physical/mineral/chemical/ biotic paleoenvironmental data might be archived in rinds is discussed. The character and classification of organic materials undergoing diagenesis are also discussed.

Archives and Copyright: Risk and Reform

This paper considers the place of the archive sector within the copyright regime, and how copyright impacts upon the preservation, access to, and use of archival holdings. It begins with a critical assessment of the current parameters of the UK copyright regime as it applies to the work of archivists, including recommendations for reform that have followed in the wake of the Gowers Review of Intellectual Property (2006-2010), the Hargreaves Review of Intellectual Property and Growth (2010-2011), the Consultation on Copyright (2011-12), as well as the government’s response thereto: Modernising Copyright (2012). It considers the various problems the copyright regime presents for archives undertaking mass digitisation projects as well as recent European and UK initiatives in this domain. It argues that the UK copyright regime, even when read in conjunction with current national and regional recommendations for reform, falls short of delivering a legal framework that would enable archivists to realise the full potential that comprehensive, universal online access to the country’s archival holdings would contribute to local and national democracy and accountability, to education, learning, and culture, and to the sense of identity and place for local people, communities and organisations. Ultimately, a case is made for the differential treatment of archives within the copyright regime – different, that is, from libraries and other related institutions operating within the cultural sector. The paper concludes with a policy recommendation that would greatly enhance the ability of archives to provide online access to their holdings, while at the same time safeguarding the economic interests of the authors and owners of copyright-protected work.

MixKMeans: Clustering Question-Answer Archives

Community-driven Question Answering (CQA) systems that crowdsource experiential information in the form of questions and answers and have accumulated valuable reusable knowledge. Clustering of QA datasets from CQA systems provides a means of organizing the content to ease tasks such as manual curation and tagging. In this paper, we present a clustering method that exploits the two-part question-answer structure in QA datasets to improve clustering quality. Our method, {\it MixKMeans}, composes question and answer space similarities in a way that the space on which the match is higher is allowed to dominate. This construction is motivated by our observation that semantic similarity between question-answer data (QAs) could get localized in either space. We empirically evaluate our method on a variety of real-world labeled datasets. Our results indicate that our method significantly outperforms state-of-the-art clustering methods for the task of clustering question-answer archives.

Archives of Working-Class Life: The Labour Movement, Working-Class Cultures and Conflict in Northern Ireland since 1945'

With Dr Seán Byers (83-page report funded by Irish Department of Foreign Affairs, in collaboration with Trademark Belfast, published online on 30 September 2016).