a b s t r a c tObjectives: Parapneumonic pleural effusions/empyema (PPE/PE) are severe complications of communityacquired pneumonia. We investigated the bacterial aetiology and incidence of paediatric PPE/PE in Germany after the introduction of universal pneumococcal conjugate vaccine (PCV) immunization for infants. Methods: Children <18 years of age hospitalized with pneumonia-associated PPE/PE necessitating pleural drainage or persisting >7 days were reported to the German Surveillance Unit for Rare Diseases in Childhood between October 2010 and June 2017. All bacteria detected in blood or pleural fluid (by culture/PCR) were included, with serotyping for Streptococcus pneumoniae. Results: The median age of all 1447 PPE/PE patients was 5 years (interquartile range 3e10). In 488 of the 1447 children with PPE/PE (34%), 541 bacteria (>40 species) were detected. Aerobic gram-positive cocci accounted for 469 of 541 bacteria detected (87%); these were most frequently Streptococcus pneumoniae (41%), Streptococcus pyogenes (19%) and Staphylococcus aureus (6%). Serotype 3 accounted for 45% of 78 serotyped S. pneumoniae strains. Annual PPE/PE incidence varied between 14 (95%CI 12e16) and 18 (95%CI 16e21) PPE/PE per million children. Incidence of S. pneumoniae PPE/PE decreased from 3.5 (95%CI 2.5e4.6) per million children in 2010/11 to 1.5 (95%CI 0.9e2.4) in 2013/14 (p 0.002), followed by a reincrease to 2.2 (95%CI 1.5e3.2) by 2016/17 (p 0.205). Conclusions: In the era of widespread PCV immunization, cases of paediatric PPE/PE were still caused mainly by S. pneumoniae and, increasingly, by S. pyogenes. The re-increase in the incidence of PPE/PE overall and in S. pneumoniae-associated PPE/PE indicates ongoing changes in the bacterial aetiology and requires further surveillance.
In the genus Phyteurna spadix-shaped spikes or capitula are composed of xerochasic poricidal capsules, holding unspecialized seeds. Phyteurna betonicifoliurn VILL., Phyteuma hemisphaericurn 1., Phyteurna scheuchzeri ALL., and Phyteurna spicaturn L. were examined in wind tunnel experiments to determine the minimum wind speed necessary for seed release, and the relationship between wind speeds and dispersal distances. In a simplified practical simulation the dispersal strategies of these species were described with a leptokurtic curve. The short-distance seed dispersal of Phyteuma hernisphaericurn allows a limited enlargement of the occupied area, while the seeds of P. scheuchzeri are dispersed more remotely from the mother plant. P. spicaturn and P. betonicifoliurn mainly disperse closely around the mother plant but provide a certain percentage of seeds for colonization of more distant areas. It is demonstrated that the dispersal modes are determined by the characteristics of fruits, infructescences, and seeds. It is also shown that plants with similar morphological organization show different dispersal patterns, which must be interpreted as a fine-tuned adaptation to the habitat with all its biotic and abiotic factors.
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