Messor barbarus is a Mediterranean harvester ant that constructs physically defined trunk routes on the ground to connect nest entrances with foraging areas. Some responses of these trunk routes to plant density (and therefore resource abundance) were analyzed by testing the preferential allocation of different parts (trunk route ends, segments and branching points) in a patchy environment. Maps of grass density in four categories and Messor barbarus trunk routes were compiled for a Mediterranean pasture in Central Spain over four consecutive years. The proportions of the density categories in each year were used to calculate random expected frequencies of the trunk route points and the predominance of higher or lower grass densities. Trunk route ends discriminate and selectively reach patches with a greater abundance of resources in all study years. Branching points are also allocated preferentially in areas with higher vegetation density, but only in years with a predominance of the higher categories of grass density. In these years, the colonies of Messor barbarus have a "phalanx" strategy at a colonial level, and branching is more profuse. Finally, trunk route segments do not indicate any preference for crossing determined vegetation densities, but rather connect successive branching points or trunk route ends by the shortest route. These results concur with a model of structural strategy change ("guerilla" - "phalanx") (Hutchings 1988) at the level of trunk routes. They are probably constituted by "transitory" sections with few branches, that expand other more profusely branched sections which are more dedicated to foraging.

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BackgroundSome patients with COPD may share characteristics of asthma; this is the so-called asthma–COPD overlap syndrome (ACOS). There are no universally accepted criteria for ACOS, and most treatments for asthma and COPD have not been adequately tested in this population.Materials and methodsWe performed a survey among pulmonology specialists in asthma and COPD aimed at collecting their opinions about ACOS and their attitudes in regard to some case scenarios of ACOS patients. The participants answered a structured questionnaire and attended a face-to-face meeting with the Metaplan methodology to discuss different aspects of ACOS.ResultsA total of 26 pulmonologists with a mean age of 49.7 years participated in the survey (13 specialists in asthma and 13 in COPD). Among these, 84.6% recognized the existence of ACOS and stated that a mean of 12.6% of their patients might have this syndrome. In addition, 80.8% agreed that the diagnostic criteria for ACOS are not yet well defined. The most frequently mentioned characteristics of ACOS were a history of asthma (88.5%), significant smoking exposure (73.1%), and postbronchodilator forced expiratory volume in 1 second/forced vital capacity <0.7 (69.2%). The most accepted diagnostic criteria were eosinophilia in sputum (80.8%), a very positive bronchodilator test (69.2%), and a history of asthma before 40 years of age (65.4%). Up to 96.2% agreed that first-line treatment for ACOS was the combination of a long-acting β2-agonist and inhaled steroid, with a long-acting antimuscarinic agent (triple therapy) for severe ACOS.ConclusionMost Spanish specialists in asthma and COPD agree that ACOS exists, but the diagnostic criteria are not yet well defined. A previous history of asthma, smoking, and not fully reversible airflow limitation are considered the main characteristics of ACOS, with the most accepted first-line treatment being long-acting β2-agonist/inhaled corticosteroids.

The germination response of different sized seeds from individuals of a Mediterranean fireprone shrub (Cistus ladanifer) was investigated in relation to pre-germination heating. A control (no heating), a low temperature during a short exposure time (50°C during 5 min), a high temperature during a short exposure time (100°C during 5 min) and a high temperature during a long exposure time (100°C during 15 min) were applied to seeds from different individual plants with different mean seed weight. These pre-germination treatments resemble natural germination scenarios for the studied species, absence of fire, low intensity pasture fire, typical Mediterranean shrub fire, and severe fire with high fuel load. Mean seed weight only showed a marginally significant positive correlation with the proportion of germinated seeds whatever the pregermination treatment. These results suggest that seed dormancy is unrelated to seed size and that under the experimental conditions used in this study, the effect of seed size on seed germination is low. Nevertheless, larger seeds could be favoured in natural conditions, especially under the high competition scenario which arise after wildfires. Control seeds showed a negative correlation between seed size and germination velocity suggesting that lighter seeds could take advantage from early germination in recruitment events in the absence of wildfires. Nevertheless, even the lower pre-germination heating treatment turns this correlation in not significant, suggesting a strong selection pressure (unrelated to seed size) for early germination after fire events. In our study, different sized seeds of C. ladanifer seem to perform better under different germination scenarios suggesting that seed size variation could be maintained by the alternation of recruitments without wildfires and recruitments after wildfire events.