Type specimens of G.E. Post in Beirut and The Natural History Museum, London

The Flora of Syria, Palestine and Sinai, a pioneer Flora of the region, was published in 1896 by George Edward Post (1838–1909). Lesser known are his series of Diagnoses plantarum novarum orientalium, published in the Journal of the Linnean Society Botany, and 10 papers, Plantae Postianae, which appeared in Swiss journals from 1890 to 1900. A greatly expanded second edition of the Flora was prepared by John Edward Dinsmore and published in Beirut in 1932 and 1933. Post's plant collection is part of the Post Herbarium (BEI), with about 63 000 specimens, that has been well maintained, despite civil war and inadequate staffing. This work involves the identification of around 150 types in BEI and BM, and improvement of the accessibility of the specimens. © 2009 The Linnean Society of London, Botanical Journal of the Linnean Society, 2009, 159, 315–321.

Posttraumatic stress symptoms in London school children following September 11, 2001: an exploratory investigation of peri-traumatic reactions and intrusive imagery

Threatening intrusive images are central to posttraumatic stress disorder. It has been suggested that intrusive imagery in the context of a sense of threat leads to the development and persistence of posttraumatic stress symptoms. This study investigates London school children's (N = 76; age 10-11 years) self-reported posttraumatic stress symptoms in response to viewing the attacks of September 11, 2001 on television. Assessments were made at two time points. A minority of participants reported moderate-severe symptoms with functional impairment at 2 months (14.5%) and 6 months (9.2%) after viewing the September 11events. After controlling for symptom stability, persistent symptoms were associated with peri-traumatic factors, notably perceiving that one's life was in danger. The combined effect of intrusive imagery and peri-traumatic life threat was associated with symptom persistence. Assessments of intrusive image content via checklist and free-report indicated that the images were directly related to September 11 and were fairly stable over time. Implications for treating children's intrusive images following stressful events are explored. (C) 2007 Elsevier Ltd. All rights reserved.

Chess endgame knowledge advances

This review of recent developments starts with the publication of Harold van der Heijden's Study Database Edition IV, John Nunn's second trilogy on the endgame, and a range of endgame tables (EGTs) to the DTC, DTZ and DTZ50 metrics. It then summarises data-mining work by Eiko Bleicher and Guy Haworth in 2010. This used CQL and pgn2fen to find some 3,000 EGT-faulted studies in the database above, and the Type A (value-critical) and Type B-DTM (DTM-depth-critical) zugzwangs in the mainlines of those studies. The same technique was used to mine Chessbase's BIG DATABASE 2010 to identify Type A/B zugzwangs, and to identify the pattern of value-concession and DTM-depth concession in sub-7-man play.

Mid-nineteenth century smoke concentrations near London

It has been proposed that Earth's climate could be affected by changes in cloudiness caused by variations in the intensity of galactic cosmic rays in the atmosphere. This proposal stems from an observed correlation between cosmic ray intensity and Earth's average cloud cover over the course of one solar cycle. Some scientists question the reliability of the observations, whereas others, who accept them as reliable, suggest that the correlation may be caused by other physical phenomena with decadal periods or by a response to volcanic activity or El Niño. Nevertheless, the observation has raised the intriguing possibility that a cosmic ray–cloud interaction may help explain how a relatively small change in solar output can produce much larger changes in Earth's climate. Physical mechanisms have been proposed to explain how cosmic rays could affect clouds, but they need to be investigated further if the observation is to become more than just another correlation among geophysical variables.