Leaf trichomes and foliar chemistry mediate defence against glasshouse thrips; Heliothrips haemorrhoidalis (Bouché) in Rhododendron simsii

Herbivore defence mechanisms are a costly diversion of resources away from growth and reproduction. Thus time-limited and tissue specific expression in critical plant parts is more efficient as defined by optimal defence theory. Surprisingly little is known about Rhododendron herbivore defence but it may be mediated by combined chemical and physical mechanisms. Rhododendron simsii Planch. survives cyclic infestations of a leaf-feeding thrips, Heliothrips haemorrhoidalis, which severely damage mature leaves but avoid terminal young leaves suggesting specific, localised defence expression. We examined correlations between the distribution of thrips and feeding damage with density of trichomes and the concentration of the diterpenoid, grayanotoxin I, a compound implicated in but not previously reported to meditate invertebrate defence in Rhododendron. Our data show that as leaves matured the number of thrips and area of feeding damage increased as trichome density and grayanotoxin I concentration decreased, this inverse correlation 10 suggesting trichomes and grayanotoxin I mediate defence in younger leaf tissue. Grayanotoxin I was tested against H. haemorrhoidalis and was toxic to immature life stages and repellent to the adult thrips, reducing numbers of first instars emerging on leaves when applied at ecologically relevant concentrations. This work demonstrates that the pattern of defensive traits in foliage of a species of Rhododendron is key to its ability to tolerate cyclic infestations of a generalist herbivore, effectively conserving vital tissues required for growth and reproduction

Lost in Transition? The Persistence of Dictatorship Mayors

Dictatorships can affect the functioning of new democracies but the mechanisms are poorly understood. We study the Pinochet dictatorship in Chile using new data and provide two findings. First, mayors appointed by Pinochet obtained a nine percentage point vote premium in the first local election in democracy. This premium is explained by an incumbency advantage and by an increase in local spending during the transition. Second, dictatorship mayors increased the vote share of right-wing political parties in democracy. We conclude that the dictatorship won "hearts and minds" before the transition and successfully maintained part of their political power

Silent pulmonary embolism in patients with proximal deep vein thrombosis in the lower limbs

BACKGROUND: One in every three patients with deep vein thrombosis (DVT) in the lower limbs may have silent pulmonary embolism (PE), but its clinical relevance has not been thoroughly studied. METHODS: We used the RIETE Registry data to study patients with proximal DVT and no PE symptoms, but with a systematic search for PE. We compared the outcome of DVT patients with silent PE and those with no PE. RESULTS: Of 2375 patients with DVT, 842 (35%) had silent PE and 1533 had no PE. During the first 15 days of anticoagulation, patients presenting with silent PE had a higher incidence of symptomatic PE events than those with no PE (0.95% vs. 0.13%; P = 0.015), with a similar incidence of major bleeding (0.95% vs. 1.63%; P = 0.09). In patients with silent PE, the incidence of PE events during the first 15 days was equal to the incidence of major bleeding (eight events each), but in those with no PE the incidence of PE events was eight times lower (3 vs. 25 bleeding events). Multivariate analysis confirmed that DVT patients with silent PE had a higher incidence of symptomatic PE events during the first 15 days than those with no PE (odds ratio, 4.80; 95% CI, 1.27-18.1), with no differences in bleeding. CONCLUSIONS: DVT patients with silent PE at baseline had an increased incidence of symptomatic PE events during the first 15 days of anticoagulant therapy. This effect disappeared after 3 months of anticoagulation

Observations and Orbits of Comets

Minor Planet Electronic Circ., No. 2017-N58 (2017).Available from the Minor Planet Center

Unsuspected pulmonary embolism in patients with cancer

BACKGROUND: The natural history of unsuspected pulmonary embolism (PE) in patients with cancer has not been thoroughly studied. METHODS: We used the RIETE Registry data to compare the clinical characteristics, treatment strategies and outcome in cancer patients with unsuspected PE and in those presenting with symptomatic, acute PE. RESULTS: Up to December 2011, 78 cancer patients with unsuspected PE and 1,994 with symptomatic PE had been enrolled. Patients with unsuspected PE more likely had colorectal cancer than those with symptomatic PE (28% vs. 13%), and less likely had prostate (3.8% vs. 10%) or hematologic (1.3% vs. 6.4%) cancer, or prior venous thromboembolism (3.8% vs. 12%). While the patients were receiving anticoagulant therapy, the incidence of PE recurrences (0% vs. 1.9%) or major bleeding (2.6% vs. 4.8%) were similar. After completion of anticoagulation, recurrent PE developed in 2.6% vs. 1.4% of patients, and major bleeding in 0% vs. 0.4%, respectively. CONCLUSIONS: Our findings suggest that the clinical characteristics and outcome in cancer patients with unsuspected PE are quite similar to those in patients with symptomatic PE

Platelet count and outcome in patients with acute venous thromboembolism

The relationship between platelet count and outcome in patients with acute venous thromboembolism (VTE) has not been consistently explored. RIETE is an ongoing registry of consecutive patients with acute VTE. We categorised patients as having very low- (450,000/\ub5l) platelet count at baseline, and compared their three-month outcome. As of October 2012, 43,078 patients had been enrolled in RIETE: 21,319 presenting with pulmonary embolism and 21,759 with deep-vein thrombosis. In all, 502 patients (1.2%) had very low-; 5,472 (13%) low-; 28,386 (66%) normal-; 7,157 (17%) high-; and 1,561 (3.6%) very high platelet count. During the three-month study period, the recurrence rate was: 2.8%, 2.2%, 1.8%, 2.1% and 2.2%, respectively; the rate of major bleeding: 5.8%, 2.6%, 1.7%, 2.3% and 4.6%, respectively; the rate of fatal bleeding: 2.0%, 0.9%, 0.3%, 0.5% and 1.2%, respectively; and the mortality rate: 29%, 11%, 6.5%, 8.8% and 14%, respectively. On multivariate analysis, patients with very low-, low-, high- or very high platelet count had an increased risk for major bleeding (odds ratio [OR]: 2.70, 95% confidence interval [CI]: 1.85-3.95; 1.43 [1.18-1.72]; 1.23 [1.03-1.47]; and 2.13 [1.65-2.75]) and fatal bleeding (OR: 3.70 [1.92-7.16], 2.10 [1.48-2.97], 1.29 [0.88-1.90] and 2.49 [1.49-4.15]) compared with those with normal count. In conclusion, we found a U-shaped relationship between platelet count and the three-month rate of major bleeding and fatal bleeding in patients with VTE