A Comparison of Nuggets and Clusters for Evaluating Timeline Summaries

There is growing interest in systems that generate timeline summaries by filtering high-volume streams of documents to retain only those that are relevant to a particular event or topic. Continued advances in algorithms and techniques for this task depend on standardized and reproducible evaluation methodologies for comparing systems. However, timeline summary evaluation is still in its infancy, with competing methodologies currently being explored in international evaluation forums such as TREC. One area of active exploration is how to explicitly represent the units of information that should appear in a 'good' summary. Currently, there are two main approaches, one based on identifying nuggets in an external 'ground truth', and the other based on clustering system outputs. In this paper, by building test collections that have both nugget and cluster annotations, we are able to compare these two approaches. Specifically, we address questions related to evaluation effort, differences in the final evaluation products, and correlations between scores and rankings generated by both approaches. We summarize advantages and disadvantages of nuggets and clusters to offer recommendations for future system evaluation

Effects of vitamin D on blood pressure, arterial stiffness, and cardiac function in older people after 1 year: BEST‐D (Biochemical Efficacy and Safety Trial of Vitamin D)

<strong>Background:</strong> The relevance of vitamin D for prevention of cardiovascular disease is uncertain. The BEST-D trial previously reported effects of vitamin D on plasma markers of vitamin D status, and the present report describes the effects on blood pressure, heart rate, arterial stiffness and cardiac function. <strong>Methods and Results:</strong> Randomized, double-blind, placebo-controlled trial of 305 older people living in UK, allocated vitamin D 4000 IU (100 μg), vitamin D 2000 IU (50 μg), or placebo daily. Primary outcomes were plasma concentrations of 25-hydroxy-vitamin D (25[OH]D) and secondary outcomes were blood pressure, heart rate and arterial stiffness in all participants at 6 and 12 months, plasma N-terminal prohormone of brain natriuretic peptide (NT-proBNP) levels in all participants at 12 months, and echocardiographic measures of cardiac function in a randomly selected subset (n=177) at 12 months. Mean (SE) plasma 25(OH)D concentrations were 50 (SE 2) nmol/L at baseline and increased to 137 (2.4), 102 (2.4) and 55 (2.4) nmol/L after 12 months in those allocated 4000 IU/day, 2000 IU/day of vitamin D or placebo, respectively. Allocation to vitamin D had no significant effect on mean levels of blood pressure, heart rate or arterial stiffness at either 6 or 12 months, nor on any echocardiographic measures of cardiac function, or plasma NT-proBNP concentration at 12 months. <strong>Conclusions:</strong> The absence of any significant effect of vitamin D on blood pressure, arterial stiffness or cardiac function suggests that any beneficial effects of vitamin D on cardiovascular disease are unlikely to be mediated through these mechanisms

Additional file 1: Table S1. of Gene expression and metabolism preceding soft scald, a chilling injury of ‘Honeycrisp’ apple fruit

Quality and maturity of fruit from ‘Honeycrisp’ orchards used for the metabolomic (all orchards) and transcriptomic (orchards A_H1, A_H2, A_H3, M, and P) analyses. (DOCX 34 kb

Additional file 8: Figure S5. of Gene expression and metabolism preceding soft scald, a chilling injury of ‘Honeycrisp’ apple fruit

Expression levels (RPKM) of Malus domestica housekeeping genes from Bowen et al. (2015) in RNA-seq analyses. (DOCX 174 kb