581 research outputs found
Vector space models of ancient Greek word meaning, and a case study on homer
Our paper describes the creation and evaluation of a Distributional Semantics model of ancient Greek. We developed a vector space model where every word is represented by a vector which encodes information about its linguistic context(s). We validate different vector space models by testing their output against benchmarks obtained from scholarship from the ancient world, modern lexicography, and an NLP resource. Finally, to show how the model can be applied to a research task, we provide the example of a small-scale study of semantic variation in epic formulae, recurring units with limited linguistic flexibility
Room to Glo: A systematic comparison of semantic change detection approaches with word embeddings
Word embeddings are increasingly used for
the automatic detection of semantic change;
yet, a robust evaluation and systematic comparison
of the choices involved has been lacking.
We propose a new evaluation framework
for semantic change detection and find that (i)
using the whole time series is preferable over
only comparing between the first and last time
points; (ii) independently trained and aligned
embeddings perform better than continuously
trained embeddings for long time periods; and
(iii) that the reference point for comparison
matters. We also present an analysis of the
changes detected on a large Twitter dataset
spanning 5.5 years.This work was supported by The Alan Turing Institute under the EPSRC grant EP/N510129/1
Mining the UK web archive for semantic change detection
Semantic change detection (i.e., identify- ing words whose meaning has changed over time) started emerging as a grow- ing area of research over the past decade, with important downstream applications in natural language processing, historical linguistics and computational social sci- ence. However, several obstacles make progress in the domain slow and diffi- cult. These pertain primarily to the lack of well-established gold standard datasets, resources to study the problem at a fine- grained temporal resolution, and quantita- tive evaluation approaches. In this work, we aim to mitigate these issues by (a) re- leasing a new labelled dataset of more than 47K word vectors trained on the UK Web Archive over a short time-frame (2000- 2013); (b) proposing a variant of Pro- crustes alignment to detect words that have undergone semantic shift; and (c) intro- ducing a rank-based approach for evalu- ation purposes. Through extensive nu- merical experiments and validation, we il- lustrate the effectiveness of our approach against competitive baselines. Finally, we also make our resources publicly available to further enable research in the domain.This work was supported by The Alan Turing In- stitute under the EPSRC grant EP/N510129/1 and the seed funding grant SF099
DUKweb, diachronic word representations from the UK Web Archive corpus
Lexical semantic change (detecting shifts in the meaning and usage of words) is an important task for social and cultural studies as well as for Natural Language Processing applications. Diachronic word embeddings (time-sensitive vector representations of words that preserve their meaning) have become the standard resource for this task. However, given the significant computational resources needed for their generation, very few resources exist that make diachronic word embeddings available to the scientific community. In this paper we present DUKweb, a set of large-scale resources designed for the diachronic analysis of contemporary English. DUKweb was created from the JISC UK Web Domain Dataset (1996–2013), a very large archive which collects resources from the Internet Archive that were hosted on domains ending in ‘.uk’. DUKweb consists of a series word co-occurrence matrices and two types of word embeddings for each year in the JISC UK Web Domain dataset. We show the reuse potential of DUKweb and its quality standards via a case study on word meaning change detection
Aid to conflict-affected countries : lessons for donors
The first section looks at the implications of conflict for aid effectiveness and selectivity. We argue that, while aid is generally effective in promoting growth and by implication reducing poverty, it is more effective in promoting growth in post-conflict countries. We then consider the implications of these findings for donor selectivity models and for assessment of donor performance in allocating development aid among recipient countries. We argue that, while further research on aid effectiveness in post-conflict scenarios is needed, existing selectivity models should be augmented with, inter alia, post-conflict variables, and donors should be evaluated on the basis, inter alia, of the share of their aid budgets allocated to countries experiencing post-conflict episodes. We also argue for aid delivered in the form of projects to countries with weak institutions in early post-conflict years. The second section focuses on policies for donors operating in conflict-affected countries. We set out five of the most important principles: (1) focus on broad-based recovery from war; (2) to achieve a broad-based recovery, get involved before the conflict ends; (3) focus on poverty, but avoid ‘wish lists’; (4) help to reduce insecurity so aid can contribute more effectively to growth and poverty reduction; and (5) in economic reform, focus on improving public expenditure management and revenue mobilisation. The third section concludes by emphasising the fact that there is no hard or fast dividing line between ‘war’ and ‘peace’ and that it may take many years for a society to become truly ‘post’-conflict’. Donors, therefore, need to prepare for the long haul.<br /
Citizen surveil-labour: Analysing Crime Stoppers and its alliance of police, media, and publics
Selectorate theory, the democratic peace, and public goods provision
We show that without a few peculiar modeling choices that are not justified by the core assumptions of the theory, selectorate theory neither unambiguously predicts the democratic peace nor that leaders of more inclusive regimes will rely upon the provision of public goods to remain in office, though they may be more likely to provide club goods. We illustrate these claims using relatively simple models that incorporate the core assumptions of their theory, while avoiding modeling choices we believe to be less appropriate. We argue for a revised version of selectorate theory, one that continues to emphasize the importance of the size of the winning coalition, yet we believe it provides a more realistic picture of democratic politics.</jats:p
Protein Phosphatase 1 (PP1) Is a Post-Translational Regulator of the Mammalian Circadian Clock
Circadian clocks coordinate the timing of important biological processes. Interconnected transcriptional and post-translational feedback loops based on a set of clock genes generate and maintain these rhythms with a period of about 24 hours. Many clock proteins undergo circadian cycles of post-translational modifications. Among these modifications, protein phosphorylation plays an important role in regulating activity, stability and intracellular localization of clock components. Several protein kinases were characterized as regulators of the circadian clock. However, the function of protein phosphatases, which balance phosphorylation events, in the mammalian clock mechanism is less well understood. Here, we identify protein phosphatase 1 (PP1) as regulator of period and light-induced resetting of the mammalian circadian clock. Down-regulation of PP1 activity in cells by RNA interference and in vivo by expression of a specific inhibitor in the brain of mice tended to lengthen circadian period. Moreover, reduction of PP1 activity in the brain altered light-mediated clock resetting behavior in mice, enhancing the phase shifts in either direction. At the molecular level, diminished PP1 activity increased nuclear accumulation of the clock component PER2 in neurons. Hence, PP1, may reduce PER2 phosphorylation thereby influencing nuclear localization of this protein. This may at least partially influence period and phase shifting properties of the mammalian circadian clock
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