Inverse gas chromatography at infinite dilution, employing alkanes and alkenes as probes, has been used to characterize the surface properties of a series of smectites of varying chemical composition. The results of this study show that the acidic centers and the interlayer distances have a great influence on the specific interaction of the smectite surface with π-bonds of alkenes. High values of the specific interaction parameter, ɛπ, are caused by the existence of strong acidic centers that are connected with interlayer cations as well as with the chemical structure of the mineral sheets. On the other hand, alkanes, whose interaction with the smectites is predominantly dispersive, are unaffected by changes in the clays’ composition and/or structure.

The sorption properties of carbon-composite materials based on montmorillonite and hydrotalcite matrices have been studied using nitrogen adsorption isotherms and inverse gas chromatography. Carbon composite materials derived from both types of inorganic precursors contain pore structure accessible for adsorbate molecules. Adsorption capacity per unit mass of these composite adsorbents is larger in the case of hydrotalcite than in montmorillonite-based materials. Exposing these materials to ambient conditions results in their hydration. Subsequent water removal by heating under vacuum increases nitrogen adsorption capacity, which is explained by the opening of the adsorption space. The water content of hydrated samples and its effect on adsorption capacity is greater for the case of hydrotalcite-based materials. No direct relationship between carbon content and adsorption properties of the materials studied is observed.

The lithium form of taeniolite served as the molecular template for carbon nanocomposites. It was intercalated with hydroxy aluminum and hydroxy aluminum-zirconium cations. Aliquots of the inorganic matrices were saturated by furfuryl alcohol followed by its interlayer polymerization. The structures were heated at 973 K in nitrogen to carbonize the polymeric precursor. Additional materials were mixed with polypropylene glycol which was then carbonized within the mineral layers. The surface properties of the nanocomposites were studied by X-ray diffraction (XRD), DTA, SEM and sorption experiments (sorption of nitrogen). The results showed that structural properties of the derived materials depend on the inorganic matrix and organic precursor. The carbon-taeniolite nanocomposites derived from polyfurfuryl alcohol as a precursor were characterized by high carbon content and a high percentage of its surface area in micropores. A broad spectrum of surface characteristics of the final products were found, depending on the history of the sample.

Condors and vultures comprise the only group of terrestrial vertebrates in the world that are obligate scavengers, and these species move widely to locate ephemeral, unpredictable, and patchily-distributed food resources. In this study, we used high-resolution GPS location data to quantify monthly home range size of the critically endangered California Condor Gymnogyps californianus throughout the annual cycle in California. We assessed whether individual-level characteristics (age, sex and breeding status) and factors related to endangered species recovery program efforts (rearing method, release site) were linked to variation in monthly home range size. We found that monthly home range size varied across the annual cycle, with the largest monthly home ranges observed during late summer and early fall (July–October), a pattern that may be linked to seasonal changes in thermals that facilitate movement. Monthly home ranges of adults were significantly larger than those of immatures, but males and females used monthly home ranges of similar size throughout the year and breeding adults did not differ from non-breeding adults in their average monthly home range size. Individuals from each of three release sites differed significantly in the size of their monthly home ranges, and no differences in monthly home range size were detected between condors reared under captive conditions relative to those reared in the wild. Our study provides an important foundation for understanding the movement ecology of the California Condor and it highlights the importance of seasonal variation in space use for effective conservation planning for this critically endangered species.

The flavonol quercetin, is one of the major flavonoids found in edible plants. The bioavailability of quercetin in humans may be influenced by the food matrix in which it is consumed as well as by its chemical and physical form. The objective of the present study was to investigate the biokinetics of quercetin from quercetin-enriched cereal bars and quercetin powder-filled hard capsules. In a randomised, single-blinded, diet-controlled cross-over study, six healthy women aged 22–28 years took a single oral dose of approximately 130 mg quercetin equivalents from either quercetin-enriched cereal bars (containing 93·3 % quercetin aglycone plus 6·7 % quercetin-4′-glucoside) or quercetin powder-filled hard capsules (100 % quercetin aglycone). Blood samples were drawn before and after quercetin administration over a 24 h period. The concentrations of quercetin and its monomethylated derivatives, isorhamnetin (3′-O-methyl quercetin) and tamarixetin (4′-O-methyl quercetin), were measured by HPLC with fluorescence detection after plasma enzymatic treatment. The systemic availability as determined by comparing the plasma concentration–time curves of quercetin was found to be five times and the cmax values six times higher after ingestion of 130 mg quercetin by quercetin-enriched cereal bars than after ingestion by quercetin capsules. In contrast, tmax did not differ significantly between the two treatments. The cmax values for isorhamnetin and tamarixetin were four and nine times higher after ingestion of quercetin by quercetin-enriched cereal bars than after ingestion by quercetin capsules. In conclusion, quercetin from quercetin-enriched cereal bars is significantly more bioavailable than from quercetin powder-filled hard capsules.

Species on oceanic islands are more likely to be endemic as well as more extinction-prone than those on continents. The Galápagos Rail Laterallus spilonotus, endemic to the Galápagos Archipelago, is presently known to occur on just four of its seven previously occupied islands and is facing multiple threats to its persistence. In this study, we compared the rail’s occurrence and abundance at 193 survey points between 2000 and 2007 on Santa Cruz Island and examined the influence of an invasion of the habitat of the species by the exotic Red-barked Quinine Tree Cinchona pubescens. We detected a 13% reduction in rail occurrence and a 31% reduction in abundance between 2000 and 2007. Rail abundance declined more in low elevation areas (< 719 m) and outside of Cinchona pubescens removal areas but not in areas where Cinchona pubescens was removed. Insofar as Galápagos Rails responded positively to management actions that promote and maintain native vegetation, we conclude that restoration projects that restore native vegetation communities benefit this apparently declining endemic bird for which more focused conservation attention is warranted.