Astaxanthin production from Haematococcus pluvialis using photobioreactors

8th European Workshop Biotechnology of Microalgae. Nuthetal, Alemanha, 7-10 de Junho

Óxidos de Nb-Ta de las pegmatitas graníticas de Giraúl, Angola

Peer ReviewedPostprint (published version

Lamprophyre-Carbonatite Magma Mingling and Subsolidus Processes as Key Controls on Critical Element Concentration in Carbonatites-The Bonga Complex (Angola)

The Bonga complex is composed of a central carbonatite plug (with a ferrocarbonatite core) surrounded by carbonatite cone sheets and igneous breccias of carbonatitic, fenitic, phoscoritic and lamprophyric xenoliths set in a carbonatitic, lamprophyric or mingled mesostase. To reconstruct the dynamics of the complex, the pyrochlore composition and distribution have been used as a proxy of magmatic-hydrothermal evolution of the complex. An early Na-, F-rich pyrochlore is disseminated throughout the carbonatite plug and in some concentric dykes. Crystal accumulation led to enrichment of pyrochlore crystals in the plug margins, phoscoritic units producing high-grade concentric dykes. Degassing of the carbonatite magma and fenitization reduced F and Na activity, leading to the crystallization of magmatic Na-, F-poor pyrochlore but progressively enriched in LILE and HFSE. Mingling of lamprophyric and carbonatite magmas produced explosive processes and the formation of carbonatite breccia. Pyrochlore is the main Nb carrier in mingled carbonatites and phoscorites, whereas Nb is concentrated in perovskite within mingled lamprophyres. During subsolidus processes, hydrothermal fluids produced dolomitization, ankeritization and silicification. At least three pyrochlore generations are associated with late processes, progressively enriched in HFSE, LILE and REE. In the lamprophyric units, perovskite is replaced by secondary Nb-rich perovskite and Nb-rich rutile. REE-bearing carbonates and phosphates formed only in subsolidus stages, along with late quartz; they may have been deposited due to the release of the REE from magmatic carbonates during the hydrothermal processes

The Borborema Pegmatite Province, NE-Brazil revisited

Considering the internal structure, mineralogical distribution and geochemical data on K-feldspar, white micas, Nb-Taoxides, tourmalines, garnet and spinel, it becomes clear that the pegmatites classified as "heterogeneous" (Johnston 1945) include examples of several types and subtypes of LCT family, Rare Element Class pegmatites if the modern pegmatite classification models of Černý & Ercit 2005 are applied: at least examples of the beryl-columbite, beryl-columbite-phosphate and complex-spodumene,complex-lepidolite (±gemmologic elbaite)and albite (± cassiterite) pegmatite types and subtypes were ntatively identified. The impossibility to determine a granitelinked zoned regional distribution of these types may be the result of the fact that there is no single central source pluton but several smaller granitic intrusions in the province and the zoning around them may overlap each other

Ecleticae philosophiae theses

Fecha de pie de imprenta tomada de títul

Massive fields temper anomaly-induced inflation: the clue to graceful exit?

A method of calculating the vacuum effective action for massive quantum fields in curved space-time is outlined. Our approach is based on the conformal representation of the fields action and on the integration of the corresponding conformal anomaly. As a relevant cosmological application, we find that if taking the masses of the fields into account, then the anomaly-induced inflation automatically slows down. The only relevant massive fields for this purpose turn out to be the fermion fields. So in supersymmetric theories this mechanism can be specially efficient, for it may naturally provide the graceful exit from the inflationary to the FLRW phase. Taking the SUSY breaking into account, the anomaly-induced inflation could be free of the well-known difficulties with the initial data and also with the amplitude of the gravitational waves.Comment: 12 pages, 2 figures. Extended version, in particular an important discussion concerning the gravitational waves adde

Evolution of pyrochlore in carbonatites: the Angola case

Peer ReviewedPostprint (published version

The distribution of rare metals in the LCT pegmatites from the Giraúl field, Angola

The Giraúl granitic pegmatite field, Angola, is composed of five pegmatite types; the most evolved belong to the beryl-columbite, beryl-columbite-phosphate and spodumene types. Pegmatites are concentrically zoned with increased grain size toward a quartz core; the most evolved pegmatites have well-developed replacement units. These pegmatites are rich in Nb-Ta oxide minerals and the field has a moderate interest for critical elements as Ta and Hf. Pegmatites are concentrically zoned with an increased grain size towards a quartz core. Tourmaline, garnet and beryl micas occur as accessory minerals. The abundance of Zr and Nb-Ta minerals increases with the evolution of the pegmatites, as well as the proportions of beryl and Li-rich minerals. The ; the Ta/(Ta+Nb) ratios in Nb-Ta oxide minerals and the Hf/(Hf+Zr) ratios in zircon also increase with the grade of evolution of the pegmatites and inside within each pegmatite body from border to inner zones, and especially in the late veins and subsolidus replacements. Textural patterns and occurrence of late veins with Ta-rich minerals suggest that Nb and especially Ta can be enriched in late hydrothermal exsolved fluids exsolved from the magma, along with Hf and other incompatible elements as Sn, U, Pb, Sb and Bi.Peer ReviewedPostprint (published version

Proteomics study of human cord blood reticulocyte-derived exosomes

Reticulocyte-derived exosomes (Rex), extracellular vesicles of endocytic origin, were initially discovered as a cargo-disposal mechanism of obsolete proteins in the maturation of reticulocytes into erythrocytes. In this work, we present the first mass spectrometry-based proteomics of human Rex (HuRex). HuRex were isolated from cultures of human reticulocyte-enriched cord blood using different culture conditions and exosome isolation methods. The newly described proteome consists of 367 proteins, most of them related to exosomes as revealed by gene ontology over-representation analysis and include multiple transporters as well as proteins involved in exosome biogenesis and erythrocytic disorders. Immunoelectron microscopy validated the presence of the transferrin receptor. Moreover, functional assays demonstrated active capture of HuRex by mature dendritic cells. As only seven proteins have been previously associated with HuRex, this resource will facilitate studies on the role of human reticulocyte-derived exosomes in normal and pathological conditions affecting erythropoiesis

International multicenter expert survey on endoscopic treatment of upper gastrointestinal anastomotic leaks

Background and study aims: A variety of endoscopic techniques are currently available for treatment of upper gastrointestinal (UGI) anastomotic leaks; however, no definite consensus exists on the most appropriate therapeutic approach. Our aim was to explore current management of UGI anastomotic leaks. Methods: A survey questionnaire was distributed among international expert therapeutic endoscopists regarding management of UGI anastomotic leaks. Results: A total of 44 % of 163 surveys were returned; 69 % were from gastroenterologists and 56 % had > 10 years of experience. A third of respondents treat between 10 and 19 patients annually. Fifty-six percent use fully-covered self-expandable metal stents as their usual first option; 80% use techniques to minimize migration; 4 weeks was the most common reported stent dwell time. Sixty percent perform epithelial ablation prior to over-the-scope-clip placement or suturing. Regarding endoscopic vacuum therapy (EVT), 56 % perform balloon dilation and intracavitary EVT in patients with large cavities but small leak defects. Regarding endoscopic septotomy, 56 % consider a minimal interval of 4 weeks from surgery and 90 % consider the need to perform further sessions. Regarding endoscopic internal drainage (EID), placement of two stents and shorter stents is preferred. Persistent inflammation with clinical sepsis was the definition most commonly reported for endoscopic failure. EVT/stent placement and EVT/EID were the therapeutic options most often chosen in patients with previous oncologic surgery and previous bariatric surgery, respectively. Conclusions: There is a wide variation in the management of patients with UGI anastomotic leaks. Future prospective studies are needed to move from an expert- to evidence- and personalization-based care