528 research outputs found

    Modeling the long term dynamics of pre-vaccination pertussis

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    The dynamics of strongly immunizing childhood infections is still not well understood. Although reports of successful modeling of several incidence data records can be found in the literature, the key determinants of the observed temporal patterns have not been clearly identified. In particular, different models of immunity waning and degree of protection applied to disease and vaccine induced immunity have been debated in the literature on pertussis. Here we study the effect of disease acquired immunity on the long term patterns of pertussis prevalence. We compare five minimal models, all of which are stochastic, seasonally forced, well-mixed models of infection based on susceptible-infective-recovered dynamics in a closed population. These models reflect different assumptions about the immune response of naive hosts, namely total permanent immunity, immunity waning, immunity waning together with immunity boosting, reinfection of recovered, and repeat infection after partial immunity waning. The power spectra of the output prevalence time series characterize the long term dynamics of the models. For epidemiological parameters consistent with published data for pertussis, the power spectra show quantitative and even qualitative differences that can be used to test their assumptions by comparison with ensembles of several decades long pre-vaccination data records. We illustrate this strategy on two publicly available historical data sets.Comment: paper (31 pages, 11 figures, 1 table) and supplementary material (19 pages, 5 figures, 2 tables

    First report of Puccinia thaliae causing rust on Canna spp. in Europe

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    Disease Notesinfo:eu-repo/semantics/publishedVersio

    Isolation of bluish anthocyanin-derived pigments obtained from blueberry surplus using centrifugal partition chromatography

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    Funding Information: This work was funded by Fundação para a Ciência e Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior (FCT/MCTES, Portugal) through national funds to iNOVA4Health (UIDB/04462/2020 and UIDP/04462/2020), the Associate Laboratory LS4FUTURE (LA/P/0087/2020) and Associated Laboratory for Sustainable Chemistry, Clean Processes, and Technologies LAQV (UIDB/50006/2020 and UIDP/50006/2020). Funding from INTERFACE Programme, through the Innovation, Technology and Circular Economy Fund (FITEC), is gratefully acknowledged. A.N.N. acknowledge FCT for the financial support received through SFRH/BD/144592/2019. J.O. acknowledge FCT her research contract (2022.00042.CEECIND/CP1724/CT0017). The authors also acknowledge Delícias do Tojal, CultiBaga, and Mirtilsul for kindly supplying the biomass. Funding Information: This work was funded by Fundação para a Ciência e Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior (FCT/MCTES, Portugal) through national funds to iNOVA4Health ( UIDB/04462/2020 and UIDP/04462/2020 ), the Associate Laboratory LS4FUTURE ( LA/P/0087/2020 ) and Associated Laboratory for Sustainable Chemistry, Clean Processes, and Technologies LAQV ( UIDB/50006/2020 and UIDP/50006/2020 ). Funding from INTERFACE Programme, through the Innovation, Technology and Circular Economy Fund ( FITEC ), is gratefully acknowledged. A.N.N. acknowledge FCT for the financial support received through SFRH/BD/144592/2019 . J.O. acknowledge FCT her research contract ( 2022.00042.CEECIND/CP1724/CT0017 ). The authors also acknowledge Delícias do Tojal, CultiBaga, and Mirtilsul for kindly supplying the biomass. Publisher Copyright: © 2023 The Author(s)Replacement of synthetic colorants with natural ones is a current marketing trend. Nevertheless, the naturally occurring blue color is rare compared to other colours. In this work, centrifugal partition chromatography (CPC) process was developed as a more efficient and sustainable alternative to reversed phase column chromatography (RP-CC) for the preparative-scale purification of portisins. The strategy began with the extraction of anthocyanins from blueberry surplus and hemi-synthesis of respective portisins. Then, the CPC method development started with the biphasic solvent system selection followed by the optimization of the operating parameters and ended up with a comparison with RP-CC. Aiming at maximizing the portisin content, process throughput, efficiency, and minimizing the environmental risk factor, the effect of sample load (100–500 mg/100 mL of column volume), mobile phase flow rate (10–20 mL/min), and rotation speed (1000–1600 rpm) was evaluated. The two-phase solvent system consisted of tert‑butyl‑methyl ether, n-butanol, acetonitrile, and water (volume ratio 2:2:1:5) acidified with 0.1 vol.% of HCl was selected. The best conditions were 464 mg of sample/100 mL of column volume, 20 mL/min of mobile phase flow rate, and 1600 rpm of rotation speed at reversed phase mode, allowing the purification of portisins by 5-fold. Compared to the RP-CC, the CPC process efficiency was 2.4 times higher, while the CPC process environmental risk factor was 5.5 times lower. Overall, this study suggests that CPC can be considered an effective, and sustainable alternative process for the preparative isolation of portisins. With this purification approach, the blueberry surplus has been valorized and a naturally derived product has been prepared, allowing its subsequent use as a natural blue colorant.publishersversionpublishe

    Development of a carotenoid-rich microalgae colorant by microencapsulation

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    Producción CientíficaDunaliella salina has been recognized as an excellent biomass source of carotenoid, which can be used as a natural orange coloring agent for food products. The most eco-friendly approach for extracting carotenoid is through supercritical carbon dioxide extraction, as it yields highly concentrated extracts while preventing pigment thermal degradation. However, there are limitations when a lipophilic extract is considered a food ingredient, in particular very difficult handling and low solubility in water-based products. The aim of this study was to develop a hydrosoluble form of a natural carotenoid-rich extract recovered from algae biomass within a biorefinery concept to be incorporated in aqueous-based food products. A two-step process was developed, starting with the emulsification of the supercritical extract into a mixture of maltodextrin and gum arabic, using soy lecithin as an emulsifier. The emulsification was followed by a spray-drying step. The impact of process variables on the encapsulation yield, efficiency, emulsion properties, and particle characteristics was studied. The resulting particles exhibited an intense orange color and good water dispersibility, facilitating uniform yellow coloring when incorporated into an aqueous-based product. Overall, spray-drying emulsions containing carotenoids derived from Dunaliella salina prove to be a promising strategy for the global market demand for natural colorants.Fundación Portuguesa para la Ciencia y la Tecnología (FCT) - (grant SFRH/BPD/79533/2011)IF Starting Grant - GRAPHYT (IF/00723/2014)Laboratorio Asociado de Química Verde LAQV y Fondo Europeo de Desarrollo Regional (FEDER) - (UID/QUI/50006/2013, POCI-01-0145-FEDER–007265)European Knowledge-Based Bioeconom (KBBE) P7 - (project 613870)Fundación Portuguesa para la Ciencia y la Tecnología (FCT) - (PEst- OE/EQB/LA0004/2011)Fundación Portuguesa para la Ciencia y la Tecnología (FCT)/Ministerio de Ciencia y Enseñanza Superior de Portugal y Fondo Europeo de Desarrollo Regional (FEDER) - iNOVA4Health (LISBOA-01-0145-FEDER-007344

    Stability analysis of cosmological models through Liapunov's method

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    We investigate the general asymptotic behaviour of Friedman-Robertson-Walker (FRW) models with an inflaton field, scalar-tensor FRW cosmological models and diagonal Bianchi-IX models by means of Liapunov's method. This method provides information not only about the asymptotic stability of a given equilibrium point but also about its basin of attraction. This cannot be obtained by the usual methods found in the literature, such as linear stability analysis or first order perturbation techniques. Moreover, Liapunov's method is also applicable to non-autonomous systems. We use this advantadge to investigate the mechanism of reheating for the inflaton field in FRW models.Comment: Latex file, 8 pages, no figures, accepted for publication in Class. & Quant. Gra

    From a heavy metal perspective, is macroalgal biomass from Madeira Archipelago and Gran Canaria Island of eastern Atlantic safe for the development of blue bioeconomy products?

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    Macroalgae are considered a valuable source of several compounds with nutritional, nutraceutical, cosmeceutical, and phar maceutical applications. They are also used for crop fertilization and biofortifcation by introducing important minerals into the soil essential for crop productivity. At the same time, however, they are known bio-accumulators of some heavy metals. In this work, we assessed the content of 7 minerals considered as heavy metals in 25 macroalgae samples, comprising 4 greens, 9 reds and 12 browns, from Madeira Archipelago, Portugal, for their potential use as blue bioeconomy products. These heavy metals included zinc (Zn) with concentrations that ranged from 1.95 – 242.65 mg kg−1 dw, nickel (Ni, 0.6 – 34.78 mg kg−1 dw), copper (Cu, 0.42 – 7.98 mg kg−1 dw), chromium (Cr, 0.47 – 45.74 mg kg−1 dw), cadmium (Cd, 0.1 – 2.58 mg kg−1 dw), lead (Pb, 0.05 – 2.79 mg kg−1 dw) and mercury (Hg, 0.03 – 8.49 µg kg−1 dw). We also analysed 22 samples of beach-cast macroalgae from Gran Canaria Island, Spain, collected from November 2016 to November 2019. The same heavy metals were assessed with their concentrations that ranged as follows: Zn (11.41 – 42.20 mg kg−1 dw), Ni (3.17 – 17.78 mg kg−1 dw), Cu (1.85 – 4.20 mg kg−1 dw), Cr (6.08 – 37.98 mg kg−1 dw), Cd (0.02 – 0.11 g kg−1 dw), Pb (0.16 –5.42 mg kg−1 dw) and Hg (3.59 – 31.00 µg kg−1 dw). These concentrations are all within the normal ranges reported in earlier studies in low industrialized areas, except for the brown algae Gongolaria abies-marina and Sargassum vulgare with high mean (±SD) Cd concentration (1.91±0.36 and 1.75±0.07 g kg−1 dw respectively). Our results suggest that most of the biomass prospected in these localities covered in the present study would be a viable source of materials for the development of a blue economy industry with emerging products following the European Union directives.info:eu-repo/semantics/publishedVersio

    Investigations of Olive Oil Industry By-Products Extracts with Potential Skin Benefits in Topical Formulations

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    © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).The by-products of olive oil industry are a major ecological issue due to their phenolic content, highly toxic organic load, and low pH. However, they can be recovered and reused, since their components have antioxidant, anti-inflammatory, and photoprotector properties. In this work, oil-in-water creams containing three different olive oil industry by-products extracts were produced without the use of organic solvents. First, the extracts were thoroughly characterized in vitro for cytotoxicity, inhibition of skin enzymes, and antioxidant and photoprotection capacities. Safety studies were then performed, including ocular and skin irritation tests, ecotoxicity evaluation, and in vivo Human Repeat Insult Patch Test. The results obtained in this initial characterization supported the incorporation of the extracts in the cream formulations. After preparation, the creams were characterized for their organoleptic, physicochemical, droplet size and rheological properties, and microbial contamination. The results showed that all formulations were semi-solid creams, with stable pH, compatible with the skin, without microbial contamination, and with the expected droplet size range. The rheological analysis showed shear-thinning behavior with yield stress, with the viscosity decreasing with increasing shear rate. The oscillatory results suggest that the creams have a strong network structure, being easily rubbed into the skin. Finally, compatibility, acceptability and antioxidant efficacy were evaluated in vivo, in human volunteers. No adverse reactions were observed after application of the formulations on skin and the cream with the highest concentrations of phenolic compounds showed the highest antioxidant efficiency. In conclusion, the results suggest that olive oil industry by-products extracts have valuable properties that favor their re-use in the cosmetic industry. The example presented here showed their successful incorporation into creams and their impact in these formulations’ appearance, pH, and rheological performance, as well as their in vivo compatibility with skin and antioxidant efficiency.This work was supported by Sovena Portugal Consumer Goods through the project Oil4Health: From Olive to Health LISBOA-01-0247-FEDER-038554, funded by the Portugal 2020 program—Programa Operacional Regional de Lisboa. This research was also funded by FCT (Fundação para a Ciência e a Tecnologia) through iMed.ULisboa UID/DTP/04138/2019 and UIDB/04138/2020), principal investigator grants CEECIND/03143/2017 (L. M. Gonçalves). Joana Marto is financed through FCT, I.P., under the Scientific Employment Stimulus—Institutional Call (CEECINST/00145/2018). Marta Martins is financed through FCT, I.P., under the Scientific Employment Stimulus—Institutional Call (CEECINST/00102/2018). The work was supported by the Marine and Environmental Sciences Centre—MARE (UIDB04292/2020; UIDP/04292/2020).info:eu-repo/semantics/publishedVersio

    At the entrance gate : students and biographical trajectories in the University of Lisbon

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    University ‘failure’ is the starting point of this article, which is based on a case study at the University of Lisbon. The objective is to discuss concepts constructing ‘school failure’ as a problem in higher education systems, with special attention being given to contemporary debates on ‘youth condition’ in strongly individualised societies. The study selects first-year students in the University of Lisbon's eight faculties in 2003–2004, to establish a social characterisation of this group by applying an extensive survey to first-year students. A database was constructed and statistical treatment of the information undertaken. This article relates these findings to school failure indicators at the university and its various faculties. As a result, we expect to sketch a social portrait of new University of Lisbon students in 2003–2004 considered as a whole and in their internal diversity, and to illustrate links between their social trajectories and secondary school failure and success indicators

    A bio-based alginate aerogel as an ionic liquid support for the efficient synthesis of cyclic carbonates from co2 and epoxides

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    Funding Information: This work was supported by Ministerio de Ciencia y Universidades (project RTI2018-097456-B-I00) and Funda??o para a Ci?ncia e Tecnologia FCT/MCTES (project PTDC/EQU-EPQ/31926/2017), UIDB/50006/2020 of the Associate Laboratory for Green Chemistry?LAQV and UIDB/00100/2020 of Centro de Qu?mica Estrutural. This work was also supported by a Short Term Scientific Mission of the CMST COST Action CM1206. A.B. Paninho is thankful to FCT for the doctoral fellowship PD/BD/52497/2014 and pos-doctoral fellowship PTDC/EQU-EPQ/31926/2017. The authors also thanks to the project ?SunStorage-Harvesting and storage of solar energy?, with reference POCI-01-0145-FEDER-016387, funded by European Regional Development Fund (ERDF), through COMPETE 2020-Operational Program. The NMR spectrometers at FCT NOVA are part of Rede Nacional de RMN (PTNMR), supported by FCT/MCTES through ROTEIRO/0031/2013? PINFRA/22161/2016 and co-financed by FEDER through COMPETE 2020, POCI, and PORL and FCT/MCTES through PIDDAC.In this work, the ionic liquid [Aliquat][Cl] was supported into alginate and silica aerogel matrices and applied as a catalyst in the cycloaddition reaction between CO2 and a bio-based epoxide (limonene oxide). The efficiency of the alginate aerogel system is much higher than that of the silica one. The method of wet impregnation was used for the impregnation of the aerogel with [Aliquat][Cl] and a zinc complex. The procedure originated a well-defined thin solvent film on the surface of support materials. Final materials were characterised by Fourier Transform Infrared Spectroscopy, N2 Adsorption–Desorption Analysis, X-ray diffraction, atomic absorption and Field Emission Scanning Microscopy. Several catalytic tests were performed in a high-pressure apparatus at 353.2 K and 4 MPa of CO2.publishersversionpublishe

    Nutritional potential and toxicological evaluation of tetraselmis sp. CTP4 microalgal biomass produced in industrial photobioreactors

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    Commercial production of microalgal biomass for food and feed is a recent worldwide trend. Although it is common to publish nutritional data for microalgae grown at the lab-scale, data about industrial strains cultivated in an industrial setting are scarce in the literature. Thus, here we present the nutritional composition and a microbiological and toxicological evaluation of Tetraselmis sp. CTP4 biomass, cultivated in 100-m3 photobioreactors at an industrial production facility (AlgaFarm). This microalga contained high amounts of protein (31.2 g/100 g), dietary fibres (24.6 g/100 g), digestible carbohydrates (18.1 g/100 g) and ashes (15.2 g/100 g), but low lipid content (7.04 g/100 g). The biomass displayed a balanced amount of essential amino acids, n-3 polyunsaturated fatty acids, and starch-like polysaccharides. Significant levels of chlorophyll (3.5 g/100 g), carotenoids (0.61 g/100 g), and vitamins (e.g., 79.2 mg ascorbic acid /100 g) were also found in the biomass. Conversely, pathogenic bacteria, heavy metals, cyanotoxins, mycotoxins, polycyclic aromatic hydrocarbons, and pesticides were absent. The biomass showed moderate antioxidant activity in several in vitro assays. Taken together, as the biomass produced has a balanced biochemical composition of macronutrients and (pro-)vitamins, lacking any toxic contaminants, these results suggest that this strain can be used for nutritional applications.Agência financiadora Fundação para a Ciencia e a Tecnologia (FCT) UID/Multi/04326/2019 ALGARED+ 5E - INTERREG V-A Espana-Portugal project 0055 Fundacao para a Ciencia e a Tecnologia (FCT) SFRH/BD/105541/2014 SFRH/BPD/81882/2011 SFRH/BPD/100627/2014 CI-ECO - POCI-01-0145-FEDER-007679 FCT UID/CTM/50011/2013 Q-PNA - FCT UID/QUI/00062/2013info:eu-repo/semantics/publishedVersio
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