Effect of ethanol on membrane fluidity of protoplasts fromSaccharomyces cerevisiae andKloeckera apiculata grown with or without ethanol,measured by fluorescence anisotropy

Summary Direct measurements of membrane fluidity by fluorescence anisotropy of protoplasts fromKloeckera apiculata andSaccharomyces cerevisiae, a low and a high ethanol tolerant strain respectively, are presented. The comparison of the behaviour of the two strains grown with or without ethanol enabled us to demonstrate the existing relationship between ethanol tolerance and membrane fluidity.     

Casearia Essential Oil: An Updated Review on the Chemistry and Pharmacological Activities

Casearia species are found in the America, Africa, Asia, and Australia and present pharmacological activities, besides their traditional uses. Here, we reviewed the chemical composition, content, pharmacological activities, and toxicity of the essential oils (EOs) from Casearia species. The EO physical parameters and leaf botanical characteristics were also described. The bioactivities of the EOs from the leaves and their components include cytotoxicity, anti-inflammatory, antiulcer, antimicrobial, antidiabetic, antioxidant, antifungal, and antiviral activities. The main components associated with these activities are the α-zingiberene, (E)-caryophyllene, germacrene D, bicyclogermacrene, spathulenol, α-humulene, β-acoradiene, and δ-cadinene. Data on the toxicity of these EOs are scarce in the literature. Casearia sylvestris Sw. is the most studied species, presenting more significant pharmacological potential. The chemical variability of EOs components was also investigated for this species. Caseria EOs have relevant pharmacological potential and must be further investigated and exploited.     

BLOEM: A spatially explicit model of bioenergy and carbon capture and storage,applied to Brazil

Bioenergy could play a major role in decarbonizing energy systems in the context of the Paris Agreement. Large-scale bioenergy deployment could be related to sustainability issues and requires major infrastructure investments. It, therefore, needs to be studied carefully. The Bioenergy and Land Optimization Spatially Explicit Model (BLOEM) presented here allows for assessing different bioenergy pathways while encompassing various dimensions that influence their optimal deployment. In this study, BLOEM was applied to the Brazilian context by coupling it with the Brazilian Land Use and Energy Systems (BLUES) model. This allowed investigating the most cost-effective ways of attending future bioenergy supply projections and studying the role of recovered degraded pasture lands in improving land availability in a sustainable and competitive manner. The results show optimizing for limiting deforestation and minimizing logistics costs results in different outcomes. It also indicates that recovering degraded pasture lands is attractive from both logistics and climate perspectives. The systemic approach of BLOEM provides spatial results, highlighting the trade-offs between crop allocation, land use and the logistics dynamics between production, conversion, and demand, providing valuable insights for regional and national climate policy design. This makes it a useful tool for mapping sustainable bioenergy value chain pathways.     

Parasitism, developmental plasticity and bilateral asymmetry of wing feathers in alpine swift, Apus melba, nestlings

The hypothesis that developmental instability is a cost of developmental plasticity is explored using the alpine swift ( Apus melba ) as a model organism. In a previous study, experimentally parasitized nestlings showed a reduced wing growth rate in the first half of the rearing period when parasites were abundant (i.e. peak infestation) and an accelerated growth rate (i.e. compensatory growth) in the second half when parasites decreased in number. This suggests that alpine swifts are able to adjust growth rate in relation to variation in parasite loads. Because developmental plasticity may entail fitness costs, the energy required to sustain compensatory growth may be invested at the expense of developmental stability, potentially resulting in larger deviations from symmetry in paired, bilateral traits (i.e. fluctuating asymmetry, FA). This hypothesis predicts higher FA in parasitized than deparasitized nestlings because of compensatory growth, and hence individuals sustaining the highest level of compensatory growth rate should exhibit the highest FA levels. Another non-mutually exclusive hypothesis argues that parasites directly cause FA by diverting energy required by host for maintenance and growth, and predicts that individuals suffering the most from parasitism during peak infestation should exhibit the highest FA levels. The present study shows that wing feathers of experimentally parasitized nestlings were more asymmetrical than those of experimentally deparasitized ones 50 days after hatching. Furthermore, in parasitized individuals FA was negatively correlated with wing growth rate during the period of peak infestation but not during the period of compensatory growth. These findings suggest that developmental homeostasis is more sensitive to parasites than to compensatory growth.     

Geographic variation in sexual dimorphism in the barn owl Tyto alba: a role for direct selection or genetic correlation?

Geographic variation in sexually selected traits is commonly attributed to geographic variation in the net benefit accrued from bearing such traits. Although natural and sexual selection are potentially important in shaping geographic variation, genetic constraints may also play a role. Although a genetic correlation between two traits may itself be the outcome of natural or sexual selection, it may indirectly reinforce the establishment and maintenance of cline variation with respect to one particular trait when across the cline different values of other traits are selected. Using the barn owl Tyto alba, a species in which the plumage of females is more reddish‐brown and more marked with black spots than that of males, I report results that are consistent with the hypothesis that both direct selection and genetic constraints may help establish and maintain cline variation in sexual dichromatism. In this species, inter‐individual variation in plumage coloration and spottiness has a genetic basis, and these traits are not sensitive to the environment. Data, based on the measurement of skin specimens, is consistent with the hypothesis that the stronger European cline variation in male spottiness than in female spottiness depends on the combined effects of (1) the similar cline variation in male and female plumage coloration and (2) the more intense phenotypic correlation between plumage coloration and spottiness in males (darker birds are more heavily spotted in the two sexes, but especially males) which is a general feature among the globally distributed barn owls. In northern Europe, male and female T. a. guttata are reddish‐brown and heavily spotted, and in southern Europe male and female T. a. alba are white, but only females display many spots. Here, I discuss the relative importance of direct selection, genetic correlation and the post‐ice age invasion of Europe by T. alba, in generating sex‐specific cline variation in plumage spottiness and non‐sex‐specific cline variation in plumage coloration.     

Do NOE distances contain enough information to assess the relative populations of multi-conformer structures?

Summary The feasibility of determining the relative populations of multi-conformer structures from NOE-derived distances alone is assessed. Without cross-validation of the NOE restraints, any population ratio can be refined to a similar quality of the fit. Complete cross-validation provides a less biased measure of fit and allows the estimation of the correct population ratio when used in conjunction with very tight distance restraints. With the qualitative distance restraints most commonly used in NMR structure determination, cross-validation is unsuccessful in providing the correct answer. Other experimental sources are therefore needed to determine relative populations of multi-conformer structures.To whom correspondence should be addressed.     

Hydrogen Peroxide Induces a Long-Lasting Inhibition of the Ca2+-Dependent Glutamate Release in Cerebrocortical Synaptosomes Without Interfering with Cytosolic Ca2+

Abstract: We studied the action of H₂O₂ on the exocytosis of glutamate by cerebrocortical synaptosomes. The treatment of synaptosomes with H₂O₂ (50–150 µ M ) for a few minutes results in a long-lasting depression of the Ca²⁺-dependent exocytosis of glutamate, induced by KCl or by the K⁺-channel inhibitor 4-aminopyridine. The energy state of synaptosomes, as judged by the level of phosphocreatine and the ATP/ADP ratio, was not affected by H₂O₂, although a transient decrease was observed after the treatment. H₂O₂ did not promote peroxidation, as judged by the formation of malondialdehyde. In indo-1-loaded synaptosomes, the treatment with H₂O₂ did not modify significantly the KCl-induced increase of [Ca²⁺]_i. H₂O₂ inhibited exocytosis also when the latter was induced by increasing [Ca²⁺]_i with the Ca²⁺ ionophore ionomycin. The effects of H₂O₂ were unchanged in the presence of superoxide dismutase and the presence of the Fe³⁺ chelator deferoxamine. These results appear to indicate that H₂O₂, apparently without damaging the synaptosomes, induces a long-lasting inhibition of the exocytosis of glutamate by acting directly on the exocytotic process.