University of Coimbra

About: University of Coimbra is a education organization based out in Coimbra, Portugal. It is known for research contribution in the topics: Population & Mitochondrion. The organization has 14318 authors who have published 43067 publications receiving 994733 citations. The organization is also known as: UC & Universidade dos Estudos Gerais.

Synergism and polymorphism in mixed surfactant systems

Abstract: Mixed surfactant systems have been, for a long time, one of the favorite areas for experimental studies on interfacial and bulk properties of surfactants. Beyond the well-known synergistic properties, with relevance to technical applications, recent studies increasingly focus on the bulk aggregation behavior. As more systematic and detailed experimental data is collected (for example, by use of scattering and direct imaging techniques), increasingly refined theoretical models are developed. Most references reviewed here clearly show both the trends. Topics such as micellar growth, micelle-to-vesicle transition and equilibrium vesicle formation in dilute systems (in particular in catanionic systems) continue to expand and sometimes pose challenges to conventional notions of surfactant self-organization. As the rich polymorphism of mixed aggregates is unraveled, the possibilities of using them for broader goals also increase (e.g. mesoporous materials and polymer-aggregate gels).

The universal red-giant oscillation pattern - An automated determination with CoRoT data

Abstract: Aims. The CoRoT and Kepler satellites have provided thousands of red-giant oscillation spectra. The analysis of these spectra requires efficient methods of identifying all eigenmode parameters.Methods. The assumption of new scaling laws allowed us to construct a theoretical oscillation pattern. We then obtained a highly precise determination of the large separation by correlating the observed patterns with this reference. Results. We demonstrate that this pattern is universal and are able to unambiguously assign the eigenmode radial orders and angular degrees. This solves one of the remaining problems of asteroseismology, hence allowing precise theoretical investigation of red-giant interiors.

Adoption, use and perception of Australian acacias around the world

Abstract: Aim To examine the different uses and perceptions of introduced Australian acacias (wattles; Acacia subgenus Phyllodineae) by rural households and communities. Location Eighteen landscape-scale case studies around the world, in Vietnam, India, Reunion, Madagascar, South Africa, Congo, Niger, Ethiopia, Israel, France, Portugal, Brazil, Chile, Dominican Republic and Hawai‘i. Methods Qualitative comparison of case studies, based on questionnaire sent to network of acacia researchers. Information based on individual knowledge of local experts, published and unpublished sources. Results We propose a conceptual model to explain current uses and perceptions of introduced acacias. It highlights historically and geographically contingent processes, including economic development, environmental discourses, political context, and local or regional needs. Four main groupings of case studies were united by similar patterns: (1) poor communities benefiting from targeted agroforestry projects; (2) places where residents, generally poor, take advantage of a valuable resource already present in their landscape via plantation and/or invasion; (3) regions of small and mid-scale tree farmers participating in the forestry industry; and (4) a number of high-income communities dealing with the legacies of former or niche use of introduced acacia in a context of increased concern over biodiversity and ecosystem services. Main conclusions Economic conditions play a key role shaping acacia use. Poorer communities rely strongly on acacias (often in, or escaped from, formal plantations) for household needs and, sometimes, for income. Middle-income regions more typically host private farm investments in acacia woodlots for commercialization. Efforts at control of invasive acacias must take care to not adversely impact poor dependent communities.

Analysis by Vibrational Spectroscopy of Seaweed Polysaccharides with Potential Use in Food, Pharmaceutical, and Cosmetic Industries

Abstract: Polysaccharides present in several seaweeds (Kappaphycus alvarezii, Calliblepharis jubata, and Chondrus crispus—Gigartinales, Rhodophyta; Gelidium corneum and Pterocladiella capillacea—Gelidiales, Rhodophyta; Laurencia obtusa—Ceramiales, Rhodophyta; Himanthalia elongata, Undaria pinnatifida, Saccorhiza polyschides, Sargassum vulgare, and Padina pavonica—Phaeophyceae, Ochrophyta) are analyzed by spectroscopic techniques. The nature of the polysaccharides (with extraction and without any type of extraction) present in these seaweeds was determined with FTIR-ATR and FT-Raman analysis of extracted phycocolloids and ground dry seaweed.