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In order to promote the use of sub-Antarctic macroalgae as food, three species of seaweeds, Macrocystis pyrifera, Pyropia columbina, and Durvillaea antarctica, were used as ingredients in a variety of dishes such as cochayuyo bread, cochayuyo hamburgers, cochayuyo fettuccine, huiro fritters, huiro breadsticks, and luche-parsley pesto. Subsequently, the nutritional value of each of the dishes was analyzed. The chemical composition, including carbohydrates, proteins, lipids, sodium, and the fatty acid (FA) content, was examined. In general, the prepared food varieties demonstrated low lipid contents (4.1 to 8.5% dry weight, dw), moderate concentrations of protein (6.9 to 12.7% dw), and highly variable contents of total dietary fiber (1.3 to 18.9% dw). The fatty acid patterns were different for all prepared dishes, and the FA profile exhibited a beneficial contribution of polyunsaturated fatty acids (PUFAs), with a preponderance of linoleic acid and α-linolenic. The chemical composition of the dishes was compared to that of similar and commonly consumed food like white bread, hamburgers, fettuccine made of dough enriched with eggs, fritters, breadsticks, and green pesto. The results suggest that macroalgae can be used as an ingredient in prepared food where they may contribute successfully to a more balanced diet and to maintain the organoleptic characteristics in commercially attractive prepared food like cochayuyo bread, cochayuyo hamburger, cochayuyo fettuccine, huiro breadsticks, and luche-parsley pesto. [ABSTRACT FROM AUTHOR]

Macrocystis pyrifera (L.) C. Agardh is a species that forms extensive underwater forests along the coastline of the ecoregion of Magellan. There, this alga is exposed to marked variation in photoperiod, temperature, and irradiance, which are modulated by daily and seasonal climatic variations. This study aims to understand the ecophysiological behavior of M. pyrifera, in a natural forest localized in Puerto del Hambre, Magellan Region of Chile, along spatial (depth) and temporal (season) gradients of physical drivers by analyzing algal responses in terms of the photosynthetic pigments and fluorescence yield. In the apical, middle, and basal fronds, the following photosynthetic parameters were seasonally measured: electron transport efficiency ( α), maximum relative rate of electron transport (rETR), saturation point (E), and pigments such as chlorophyll a (Chl a), chlorophyll c (Chl c), and fucoxanthin. Both seasonal and stratified variations were observed. In autumn, α was decreased in the middle fronds (0.136 ± 0.030 (μmol photons m s)) with respect to apical and basal fronds of autumn. For parameters such as E, this decrease was observed relative to the depth gradient, with significant differences ( p < 0.05) between distinct fronds. rETR was high in the apical fronds in spring, autumn, and winter. High Chl a concentration was maintained in all seasons, while the concentration of Chl c in the apical fronds tended to be lower. The concentration of fucoxanthin remained stable without significant differences between dissimilar types of fronds, for seasons (spring, summer, autumn, and winter). The Chl a/Chl c ratio increased with depth, while the Chl a/fucoxanthin ratio varies seasonally. Variations of light intensity in a natural population in a depth gradient and pigment variations in M. pyrifera with the depth stratification reveal the behavior of these algae in the ecoregion of Magellan where Chl a, through the apical fronds, could be regulating the photosynthetic activity of the plants at stratification level. Furthermore, the increase in Chl c and fucoxanthin towards the middle and basal fronds showed similar trends as those measured for α, thus signifying higher photosynthetic efficiency at greater depth. Overall, our results indicate marked seasonal and depth acclimation to different environmental conditions. This study is the first of its kind for the ecoregion of Magellan in which M. pyrifera represents a keystone species of utmost ecological significance. [ABSTRACT FROM AUTHOR]

Seasonal environmental changes may significantly influence macroalgal diversity and biomass. Cryptogam species richness increases towards the poles, especially in sub-Antarctic environments. Yet, subpolar seaweed biodiversity and ecophysiology remain understudied even though it is essential for the management and sustainability of endemic species of significant economic interest (e.g., Gigartina skottsbergii). We evaluate the seasonality and ecophysiology of the different life phases of the rhodophyte G. skottsbergii by analyzing variation in fluorescence yield and photosynthetic pigment composition. There were significant seasonal differences in maximum relative electron transport rate (rETR) between gametophyte and tetrasporophyte phase, and between reproductive and vegetative specimens. Photosynthetic efficiency (α) was not significantly different between reproductive states of G. skottsbergii. We found significant differences in mean concentrations of allophycocyanin (APC), phycocyanin (PC), and chlorophyll a (Chl a) between gametophyte and tetrasporophyte phases. Results obtained provide new insight into seasonal acclimation patterns of an ecologically important species, which can be used for the design of appropriate management and cultivation strategies of G. skottsbergii towards the restoration of natural populations in fragile, subpolar regions where some of the last, relatively undisturbed communities of G. skottsbergii still remain. [ABSTRACT FROM AUTHOR]

Imipenem was successfully used to treat a case of subdural empyema complicated by multiple cerebral abscesses, in which surgery and therapy with other antibiotics had previously failed. Imipenem concentrations in serum, cerebrospinal fluid and the cerebral abscess were much higher than the MICs for the infecting organisms, qualifying this antibiotic as an effective option in therapy of suppurative intracranial infections. [ABSTRACT FROM AUTHOR]