Composition of the essential oil from cell suspension cultures of Achillea millefolium ssp. millefolium

The composition of the essential oil isolated from Achillea millefolium L. ssp. millefolium cell suspension cultures was analysed by GC and GC-MS. The yield of the oil obtained by hydrodistillation or a simultaneous distillation -extraction of these cultures, harvested at days 8–10 (end of exponential phase), was 0.001 % (w/w). The analysis of the volatiles showed the presence of thirteen components; monoterpenes amounted to 5%, sesquiterpene hydrocarbons attained 40%, while eugenol, demethoxyencecalin and two unidentified compounds amounted to 45% of the total oil. Several methods were tested in an attempt to increase the essential oil production by the cultures: growth on solid medium, growth in light, use of a different culture medium, elicitation with cellulase or yeast extract, and growth in a two-phase system. Of the different methods tested, the growth in B5⁺ medium with Miglyol 812 led to the highest essential oil yield (0.002%, w/w), and resulted in a more diverse oil composition.     

An unusual presentation of paracoccidioidomycosis in an AIDS patient: A case report

A case of paracoccidioidomycosis presenting as a solitary pulmonary nodular lesion in a patient with acquired immunodeficiency syndrome (AIDS) is presented. This case illustrates that restricted lung lesions can also be found and diagnosed in immunodeficient patients. This revised version was published online in June 2006 with corrections to the Cover Date.     

Time course of catalase and superoxide dismutase during acclimatization and growth of micropropagated Calathea and Spathiphyllum plants

Catalase and superoxide dismutase (SOD) activities were followed in leaves during ex vitro acclimatization and growth of micropropagated Spathiphyllum floribundum Schott Petite and Calathea louisae Gagnep Maui Queen. During acclimatization of both plants catalase activity increased, reaching a maximum 4 weeks after transplantation, while total superoxide dismutase activity increased with plant growth reaching a maximum in the 24th week. Variations in the pattern of catalase and SOD isoforms were observed; a second Mn-SOD band appeared in Spathiphyllum 12 weeks after transfer from in vitro, while in Calathea plants an additional Mn-SOD form was present from the second until the fourth week after transplantation. The observed changes reflect the plants' capacity to develop antioxidant mechanisms during acclimatization. These findings indicate that the adaptation of micropropagated plants to ex vitro conditions is more extended in time than generally accepted.     

Diversity and endemism of angiosperms in the Gulf of Guinea islands

The richness of flowering plants (1666 native taxa) and the originality of the flora of the islands of the Gulf of Guinea are remarkable. The flora of Bioko shows the highest diversity in terms of families, genera and species of angiosperms but, due to its proximity to the mainland, the level of endemism is relatively low. The number of endemics in the four islands has suffered a decrease in the last years, due to taxonomic changes. Currently, 176 endemic taxa of angiosperms are recognized. Most of the endemic taxa are under-collected and information is lacking on their biology and distribution, hence the need for inventory work on the flora of the islands. A measure of the similarity between the floras of the islands can be given by determination of genera in common. The results are comparable to those obtained with Exell and Wild's quotient of affinity and show a great similarity between neighbouring islands. The presence of afromontane elements and several palaeoendemics in the mountain rain forest of the islands is notable and makes the study of its flora a priority for research.     

A role for calmodulin in organelle membrane tubulation.

Membrane tubules of uniform diameter (60-80 nm) and variable lengths have been seen to extend from the main bodies of the Golgi complex, trans Golgi network (TGN), and endosomes. In the case of endosomes, these tubules appear to mediate membrane and receptor recycling events. Brefeldin A (BFA) is a potent drug that completely blocks coated vesicle formation from the Golgi complex and TGN, but at the same time causes the enhanced formation of membrane tubules from these same organelles. Recently, experiments have shown that calmodulin antagonists inhibit the transport of receptors out of endosomes, perhaps by inhibiting the formation of recycling tubules. Using the potent calmodulin-specific antagonists N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7), N-(4-aminobutyl)-5-chloro-2-naphthalenesulfonamide (W-13), and N-(4-aminobutyl)-5-chloro-1-naphthalenesulfonamide (C-1), we found that the recycling of transferrin from endosomes to the cell surface was significantly inhibited, resulting in the formation of enlarged endosomal vacuoles. In addition, these same calmodulin antagonists also potently inhibited the formation of BFA-stimulated membrane tubules from the Golgi complex, TGN, and endosomes. In the case of the Golgi complex, failure to form tubules resulted in the inhibition of BFA-stimulated retrograde transport to the endoplasmic reticulum. These results suggest that calmodulin is a general regulator of membrane tubulation and is capable of influencing the morphology of several organelles.     

Preservation of oocyte and granulosa cell morphology in bovine preantral follicles cultured in vitro

Described in the present paper is a culture system that preserves oocyte and granulosa cell morphology in bovine preantral follicles during 5 d in vitro. The effects of additional hypoxanthine and energy substrata (i.e., pyruvate and glutamine) on the morphology of cultured preantral follicles were investigated. It was shown that addition of a mixture of pyruvate, glutamine and hypoxantine to the culture medium increased the percentage of follicles with an intact oocyte from 29.4 to 78.6%. Morphological criteria are described to discriminate between normal and degenerated preantral follicles during culture by inverted microscopy. In addition, the importance of histological evaluation to judge the quality of oocyte and granulosa cells is demonstrated.     

Turbidity amplifies the non‐lethal effects of predation and affects the foraging success of characid fish shoals

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Eltonian shortfall due to the Grinnellian view: functional ecology between the mismatch of niche concepts

A number of recognized shortfalls currently exist in biology. They are related to 1) a disparity between the species described and the actual number of species; 2) uncertainties in species’ geographical distribution; 3) scarcity of species abundance data and 4) a lack of evolutionary data. Here, we discuss how attempts to solve the Eltonian shortfall (scarcity of knowledge about intra‐ and interspecific interactions, responses of species to environment and the effects of species on ecosystems) based on functional ecology must be aware of the pitfalls of using a Grinnellian view (broad scale) to address local questions (Eltonian scale). Since the characterization of species’ requirements and their effects on the environment (Eltonian niche) is based on functional traits, it is important to recognize that the Grinnellian niche is focused on the requirements but not the effect of species on a given habitat. By neglecting the dichotomy between the Eltonian and Grinnellian niches, choosing traits based on large‐scale datasets to address local questions to describe the niche of a species may lead to two pitfalls. The first applies to situations where traits that may predict potential distribution and coexistence at large scales (Grinnellian view) are often not suitable for explaining coexistence at local scales (Eltonian view). Since the Eltonian niche comprises the requirements and impacts of species at a local scale, the second pitfall is that the selection of traits only based on their significance at coarse scales may ignore the distinction between response and effect traits. We present a theoretical framework that explores the Eltonian shortfall, and discuss possible solutions. We provide a conceptual basis to aid in the choice of traits with respect to niche concepts and population ecology for dealing with the Eltonian shortfall.