Sex and age differences in reflectance and biochemistry of carotenoid‐based colour variation in the great tit Parus major

The plumage coloration in great tits (Parus major) is the subject of much behavioural and ecophysiological research, yet there is a lack of analyses of the natural colour variation and its mechanisms. We used reflectance spectrometry and high‐performance liquid chromatography to explore individual, sexual and age‐related variation in carotenoid coloration and pigmentation, paramount to the often presumed, but rarely substantiated, costs and ‘honesty’ of carotenoid displays. In adults, we found that sex was the strongest predictor of ‘brightness’ (higher in males) and of ‘hue’ (longer wavelength in females). There was no sex difference in ‘carotenoid chroma’ or carotenoid content of feathers which also was unrelated to adult age (1 or 2+ years) and condition. Similar patterns were revealed for nestlings. Regarding the biochemical ‘signal content’, ‘carotenoid chroma’, but not ‘hue’, was significantly related to the carotenoid content (lutein and zeaxanthin) of feathers. These results refute the previously assumed exaggeration of carotenoid pigmentation in male great tits, and question the condition‐dependence of carotenoid coloration in this species. However, the sexual dimorphism in total reflectance or ‘brightness’, most likely due to melanins rather than carotenoids, may have implications for signalling or other adaptive explanations that need to be explored. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 95 , 758–765.     

Autologous bone marrow–derived cells for venous leg ulcers treatment: a pilot study

Background

Chronic venous leg ulcers (VLUs) are a common problem in clinical practice and available treatments are not satisfactory. The use of adjuvant therapies in combination with lower limb compression may lead to improved healing rates. Chronic wounds are candidates for new strategies in the emergent field of regenerative medicine. Bone marrow–derived cells (BMDCs) contain cells and secrete cytokines known to participate in wound healing. Thus, BMDC therapy seems a logical strategy for the treatment of chronic wounds. Our objective was to evaluate feasibility, safety and initial clinical outcome of autologous BMDC therapy associated with standard treatment in patients with VLUs.

Recovery of South African fynbos vegetation following alien woody plant clearing and fire: implications for restoration

Abstract The recovery of fynbos vegetation after invasion by dense stands of alien trees, and clearing by either ‘burn standing’, ‘fell and burn’, or ‘fell, remove and burn’ treatments, was investigated in two watersheds in the Western Cape Province, South Africa. Native plant density, cover, functional and biological guilds and species richness were compared with matched control sites that were not invaded, but were burnt in the same fires. Species richness was lower for invaded sites compared to controls, at all scales measured (up to 2000m²). Species area curves for invaded sites did not converge with those of controls, indicating that lower richness at smaller scales was not compensated by increased species survival at a larger scale. Indigenous plant density and cover were lower for invaded sites compared to controls. Overall, treatment differences were non‐significant, but the ‘burn standing’ treatment caused the least change to vegetation variables, and the ‘fell, remove and burn’ and ‘fell and burn’ treatments caused greater, similar changes. Changes to the guild structure of the recovering fynbos stands differed among treatments, and indicated that the ‘fell and burn’ treatment had the greatest negative effect on guild survival. In the ‘fell and burn’ treatment, which resulted in an exceptionally intense fire, only non‐mycorrhizal graminoids (predominantly myrmecochores) persisted relatively well. Because of practical problems associated with the ‘burn standing’ and ‘fell, remove and burn’ treatments, managers often have little option but to apply the ‘fell and burn’ treatment. Our results illustrate the dangers of this, and highlight the need for intervention before areas become densely invaded. They also highlight the need for effective biological control agents to reduce rates of spread of aggressively invasive species.     

Responses of an oligophagous beetle species to rearing for several generations on alternative host‐plant species

1. Imprinting and rearing on alternative host‐plant species over several generations may affect performance and preferences of herbivorous insects. In this study, the adjustment potential to alternative hosts was investigated in the oligophagous beetle Phaedon cochleariae (F.) (Coleoptera: Chrysomelidae). 2. A population that had been reared for several generations on Brassica rapa was split and transferred to either one of the alternative Brassicaceae species, Sinapis alba and Nasturtium officinale, or was kept on B. rapa for continuous rearing. After 10 generations, a subset of the Sinapis and Nasturtium populations was tested again on the original host species, B. rapa. Larval performance and adult preferences were tested. 3. In the second generation, beetles performed better (higher body mass and faster larval development) on B. rapa than on the two alternative species. No evidence for imprinting was found. After 10 generations of selection on the alternative plant species, the performance of the beetles on these species improved. This effect was more pronounced on S. alba than on N. officinale. However, the performance on B. rapa after 10 generations of selection on the alternative species was unaffected, and was nearly equal to the insects kept continuously on B. rapa, with slight deviations only in the lines selected on N. officinale. 4. Most females preferred to oviposit on B. rapa independent of their experience, suggesting a genetic fixation and/or a positive relationship between larval performance and adult preference. Preferences may have been also driven by physical leaf characteristics.     

Evaluation of a Bioassay for Cytokinins Using Soybean Hypocotyl Sections

The dose-response curves of several cytokinins were investigatedin a soybean hypocotyl bioassay. Zeatin riboside, zeatin-O-ß-D-glucoside,dihydrozeatin, and dihydrozeatin riboside produced linear responsesparallel to that for zeatin. The hypocotyl section assay wassuperior to the conventional soybean callus assay because theresponse (log₁₀ transformed data) was linear, exhibited lowvariability, and was more reproducible and more sensitive. Theassay was quicker to perform and required less cytokinin.     

Terminology used in the description of bennettitalean cuticle characters

Details of the bennettitalean stomatal apparatus, trichome bases and other cuticular features as seen in the light and scanning electron microscopes are described and an updated scheme of terminology is presented.     

Effect of Water Stress on Pigment Formation in Quercus Species

The effect of water stress in three Quercus species belongingto different habitats is investigated. Chlorophyll concentrationdecreased in all Quercus species with the greatest decreaseoccurring in Quercus robur. An increase of total carotenoidcontent was observed in Quercus coccifera and Quercus ilex,while in Q. robur water stress effected a carotenoid contentreduction. Anthocyanins increased with decreasing relative watercontent in the three Quercus species, the largest increase occurringin Q. coccifera. A correlation between xerophytic characterand pigment concentration is discussed.