142 research outputs found

    Validation and quality assurance applied to goat milk chemical composition: minerals and trace elements measurements

    Get PDF
    In the present study, quality assurance programmes were implemented to validate and control the analytical methodologies used for the characterization of minerals and trace elements in goat milk from Portuguese breeds. With the exception of chloride that was determined by potentiometric titration, all the other elements were determined by spectroscopic techniques after different sample decomposition: P was measured by ultraviolet-visible molecular absorption spectrometry, Ca, Fe, K, Mg, Mn, Na and Zn by flame atomic absorption spectrometry and Cd, Co, Cr, Cu, Mo, Ni and Pb by electrothermal atomic absorption spectrometry. The methods performance characteristics, namely specificity, limit of detection, limit of quantification, working range, precision and trueness were evaluated. Measurement uncertainty was expressed in terms of precision and trueness. Precision under intralaboratory reproducibility conditions was estimated from triplicate analysis, and the trueness component was estimated in terms of overall recovery using either skim milk powder certified reference materials or spiked samples. The results obtained are discussed on the basis of the performance criteria required by EC regulations to verify when a method is suitable for food control. The methods used for the characterization of minerals and trace elements in goat milk complied with EC requirements since there was no matrix influence, the Horrat values were < 2.0, recoveries were within the interval 1.00 ± 0.10 for minerals and 1.00 ± 0.20 for trace elements and the combined uncertainty of the results were lower than the maximum standard uncertainty calculated using the uncertainty function approach. In relation to the limits of detection and quantification, the limits obtained for Pb were lower than those specified by EC regulation

    Are organic falls bridging reduced environments in the deep sea?: Results from colonization experiments in the Gulf of Cadiz

    Get PDF
    Organic falls create localised patches of organic enrichment and disturbance where enhanced degradation is mediated by diversified microbial assemblages and specialized fauna. The view of organic falls as “stepping stones” for the colonization of deep-sea reducing environments has been often loosely used, but much remains to be proven concerning their capability to bridge dispersal among such environments. Aiming the clarification of this issue, we used an experimental approach to answer the following questions: Are relatively small organic falls in the deep sea capable of sustaining taxonomically and trophically diverse assemblages over demographically relevant temporal scales Are there important depth- or site-related sources of variability for the composition and structure of these assemblages? Is the proximity of other reducing environments influential for their colonization? We analysed the taxonomical and trophic diversity patterns and partitioning (α- and β-diversity) of the macrofaunal assemblages recruited in small colonization devices with organic and inorganic substrata after 1-2 years of deployment on mud volcanoes of the Gulf of Cádiz. Our results show that small organic falls can sustain highly diverse and trophically coherent assemblages for time periods allowing growth to reproductive maturity, and successive generations of dominant species. The composition and structure of the assemblages showed variability consistent with their biogeographic and bathymetric contexts. However, the proximity of cold seeps had limited influence on the similarity between the assemblages of these two habitats and organic falls sustained a distinctive fauna with dominant substrate-specific taxa. We conclude that it is unlikely that small organic falls may regularly ensure population connectivity among cold seeps and vents. They may be a recurrent source of evolutionary candidates for the colonization of such ecosystems. However, there may be a critical size of organic fall to create the necessary intense and persistent reducing conditions for sustaining typical chemosymbiotic vent and seep organisms

    Information representation in Displaced Archives: a meta-synthesis

    Get PDF
    The phenomenon of displaced archives emerges in the scientific literature as a kind of wicked problem. In addition to the conceptual diversity associated with this phenomenon present in the scientific literature from various fields (e.g., removed archives, migrated archives, seized archives, alienated archives, captured archives, diasporic archives, expatriated/repatriated archives, estray archival, disputed archival claims, replevin, etc.), there is a tendency in the scientific community to adopt the concept of displaced archives as a possible hypernym. The most recent definition of displaced archive is found in the report issued by the International Council on Archives through the Expert Group on Shared Archival Heritage, understood as "archives removed from the place of their creation, where the ownership of the archives is disputed by two or more parties" (Lowry 2020, 5). Nevertheless, one of the problems that makes this phenomenon a particular case is whether we can identify archives that are in the condition of displaced without there necessarily having to be claimant party(ies) for that purpose. Although the most recurrent focus in addressing this phenomenon has been around the problems of restitution, repatriation, return or relocation, the identification and, more incisively, the representation of these documentary sets have remained obscured in scientific discourse. According to Winn (2015), one of the limiting factors in the identification of displaced archives consists, among others, in the inexistence of information access tools. For Lowry, "the catalogue is the key" (2017a, 8), not only as an instrument of access to information where the processes of organization and description are materialized with a view to its retrieval and access, but also as a mechanism of information representation that derives from the powers of archival mediation. Studies on information representation suggest that, in the postmodern archival stream, it is not possible to ensure neutrality or impartiality in the representation of the content and structure of a fonds (MacNeil 2012) in finding aids. Such archival descriptions are supported by interpretative approaches that depend on the description and access policies adopted by custodians, which are not unrelated to the political, historical, socio-cultural, and institutional contexts of the environment where they were produced. Considering that the finding aids can be genologically diverse (e.g., catalogues, inventories, guides, scripts, directories, indexes and databases), it is considered more productive to focus on the representation of archival information, from the perspective of how a "fluid, evolving, and socially constructed practice" (Yakel 2003, 2) is constituted as "the core of archival description produced to facilitate access to archival materials in the background of their creation and custodial history" (Zhang 2012, 49). Considering that some of the studies on archival information representation have been problematized with greater incidence, although incipient, in Knowledge Organization and Information Science (Barros and Sousa 2020; Aguiar and Kobashi 2013; Tognoli 2013; Vital, Medeiros, and Brascher 2017; Corujo and Freitas 2021; Tognoli and Guimarães 2011; 2012; Troitiño Rodriguez 2018; Hjørland 2002), these studies have largely confined themselves to material and technical processes, physical (u. g., arrangement) and intellectual (u. g., classification and description), of concepts that conform to the bureaucratic dimension of the producers and/or custodial entities. In what concerns the displaced archives, the phenomenon itself challenges the core concepts of Archival Science, especially how these disputed documentary sets are represented from the point of view of provenance, integrity, organicity and how these representations are (re)constructed or destroyed in the process of archival mediation. Based on these aspects, and given the scarcity of studies on this topic, this article focuses on how the representation of information about archives removed from their original social and territorial contexts has been addressed in the scientific literature. Thus, we intend to conduct a survey of scientific literature that informs about the trajectory of the information representation process from the removal process to the claim by the dispossessed communities that can be theoretically relevant to the scope of Knowledge Organization. Thus, based on the above, it justifies performing a synthesis of knowledge from scientific literature called meta-synthesis (Sandelowski and Barroso 2010; Grant and Booth 2009; Finfgeld-Connett 2018). Thus, this article is structured as follows: section 2.0 formulates the starting question and research objectives; section 3.0 outlines the methodological assumptions for this type of qualitative literature synthesis; section 4.0 presents the results of the empirical investigation; section 5.0 makes concluding remarks around limitations and implications, as well as future lines of research.info:eu-repo/semantics/submittedVersio

    Below the Nation State: Power Asymmetry and Jurisdictional Boundaries around the Archives of Madeira Archipelago

    Get PDF
    The main purpose of this chapter is to describe a case study developed in a sub-national context between the Autonomous Region of Madeira and the National Archive ‘Torre do Tombo’ (ANTT). Our analysis will focus theoretically on the etiologies of dispossession and empirically on a case study. Thus, the main questions that will lead this case study are: ‘Why were the Madeiran fonds taken in the past to or by ANTT?’ and ‘How were these Madeiran fonds represented in finding aids provided by ANTT and the RAM?’. Finally, based on nissological critiques,13 we will define and contextualise the notion of sub-national displaced archives as an underresearched subset of disputed archival claims, in order to reveal some particular aspects of this phenomenon.info:eu-repo/semantics/publishedVersio

    Cork extractives exhibit thermo-oxidative protection properties in polypropylene-cork composites and as direct additives for polypropylene

    Get PDF
    The thermo-oxidative stability of polypropylene (PP) in composites containing 15 wt.% of cork and the performance of selected cork extracts as stabilizing additives for PP was evaluated by Oxidation Induction Time (OIT) and by Oxidation Onset Temperature (OOT). The results showed that cork increases the OIT of PP in the composite and it was identified that the cork extractives fraction is responsible for such behavior. Selected cork extracts with high antioxidant capacity (determined by dpph radical scavenging and oxygen reactive absorbance capacity assays) were compounded by extrusion with PP in 0.5 and 1.5 wt.%. It was found that the ethanol extract is the most effective as thermo-oxidative stabilizer for PP. At the loading level of 1.5%, the OIT increases from 3.8 (neat PP) to 29.7 min at 200 Â°C and from 1.2 (neat PP) to 9.0 min at 220 Â°C. The OOT also increases from 216 Â°C (neat PP) to 247 Â°C. Mechanical tests, performed on PP loaded with the cork extracts, showed that the presence of these extracts has no significant effect on the polymer mechanical performance. The results demonstrate the suitability of cork as a source of thermo-oxidative stabilizing additives for the formulation of polyolefins, and enable the exploitation of new routes of cork valorization.The authors are grateful to Amorim Cork Composites for providing the cork powder raw material. Ivo Aroso and Emanuel Fernandes are grateful for financial support of FCT through grants SFRH/BD/42273/2007 and SFRH/BPD/96197/2013, respectively. Funding was also granted from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no REGPOT-CT2012-316331-POLARIS and from Project "Novel smart and biomimetic materials for innovative regenerative medicine approaches (Ref.: RL1-ABMR-NORTE-01-0124-FEDER-000016)" co-financed by North Portugal Regional Operational Programme (ON.2 - O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF)

    Functionalized cork-polymer composites (CPC) by reactive extrusion using suberin and lignin from cork as coupling agents

    Get PDF
    High density polyethylene (HDPE) and cork powder were compounded in a co-rotating twin-screw extruder to obtain cork-polymer composites (CPC) with improved properties. Benzoyl peroxide (BPO) was used as initiator agent, and suberin or lignin isolated from cork enhanced filler-matrix bonding and promoted mechanical reinforcement with environmental benefits. The novel composites were characterised in terms of dimensional stability, evolution of morphology, thermal and mechanical properties and their performance was compared with that of composites containing polyethylene-grafted maleic anhydride (PE-g-MA) as coupling agent. As expected, composites with coupling agent present higher mechanical properties, lower water uptake and thickness swelling variation. Suberin acts as plasticizer with antioxidant benefits, while lignin works as a coupling agent, improving tensile modulus and maximum strength. Increasing lignin content does not improve the mechanical properties but improves thermal stability.The work was performed within the project of Corticeira Amorim S.G.P.S. on the development of new products based in/with cork. The authors gratefully acknowledge the financial support, through the COMPETE/QREN/EU funding program in the project with acronym NovelComp (QREN FCOMP-01-0202-FEDER-003107). The authors acknowledge the Portuguese Foundation for Science and Technology (FCT) and POPH/FSE for the doctoral Grants to E.M.F. (SFRH/BD/71561/2010) and I.M.A. (SFRH/BD/42273/2007)

    Nota de Apresentação

    Get PDF
    Desinformação, informações falsas, infodemia, pós-verdade, entre muitas outras denominações, constituem trending topics, isto é, os assuntos do momento que emergem em diversos domínios científicos como epifenómenos de uma disfuncionalidade epistemológica, que se define por uma “nova guerra pela verdade” (D’Ancona, 2017). Trata-se, também, de uma crise de autoridade (Enroth, 2021), principalmente de índole política, já entretanto indicada por Arendt (1967), que se carateriza por um embate dialético por uma narrativa de legitimação que não tem necessariamente de ter por base o valor da verdade. Os efeitos ponerológicos (Łobaczewski, 2006), especialmente como a desinformação ou informações falsas no âmbito da saúde (u. g., contexto pandémico da COVID19, causada pelo vírus SARS-CoV-2), no combate às alterações climáticas, nas questões migratórias ou no combate à corrupção, podem gerar efeitos sindémicos na sociedade, minando a confiabilidade das instituições democráticas, quando muito desencadear mudanças tectónicas no plano político, cultural e ambiental.info:eu-repo/semantics/publishedVersio

    The Role of Rosmarinic Acid on the Bioproduction of Gold Nanoparticles as Part of a Photothermal Approach for Breast Cancer Treatment.

    Get PDF
    Breast cancer is a high-burden malignancy for society, whose impact boosts a continuous search for novel diagnostic and therapeutic tools. Among the recent therapeutic approaches, photothermal therapy (PTT), which causes tumor cell death by hyperthermia after being irradiated with a light source, represents a high-potential strategy. Furthermore, the effectiveness of PTT can be improved by combining near infrared (NIR) irradiation with gold nanoparticles (AuNPs) as photothermal enhancers. Herein, an alternative synthetic method using rosmarinic acid (RA) for synthesizing AuNPs is reported. The RA concentration was varied and its impact on the AuNPs physicochemical and optical features was assessed. Results showed that RA concentration plays an active role on AuNPs features, allowing the optimization of mean size and maximum absorbance peak. Moreover, the synthetic method explored here allowed us to obtain negatively charged AuNPs with sizes favoring the local particle accumulation at tumor site and maximum absorbance peaks within the NIR region. In addition, AuNPs were safe both in vitro and in vivo. In conclusion, the synthesized AuNPs present favorable properties to be applied as part of a PTT system combining AuNPs with a NIR laser for the treatment of breast cancer

    Production of Poly(vinyl alcohol) (PVA) fibers with encapsulated natural deep eutectic solvent (NADES) using electrospinning

    Get PDF
    Functionalized electrospun fibers are of great interest for biomedical applications such as in the design of drug delivery systems. Nevertheless, in some cases the molecules of interest have poor solubility in water or have high melting temperatures. These drawbacks can be overcome using deep eutectic solvents. In this work, poly(vinyl alcohol) (PVA), a common biodegradable biopolymer, was used to produce new functionalized fibers with the eutectic mixture choline chloride:citric acid in a molar ratio of (1:1) ChCl:CA (1:1), which was used as a model system. Fibers were produced from an aqueous solution with 7.8% (w/v) and 9.8% (w/v) of 95% hydrolyzed PVA and a 2% (v/v) of ChCl:CA (1:1). Smooth, uniform fibers with an average diameter of 0.4 μm were obtained with a content of 19.8 wt % of ChCl:CA (1:1) encapsulatedFCT/MEC through the project ENIGMA - PTDC/EQU-EPR/121491/2010, and the project PEst-C/ EQB/LA0006/2013. European Union’s Seventh Framework Programme (FP7/2007-2013) under grant agreement n°REGPOT-CT2012-316331-POLARIS, and from the Project “Novel smart andbiomimetic materials for innovative regenerative medicine approaches (Ref.: RL1 - ABMR - NORTE-01-0124-FEDER-000016) ”cofinanced by the North Portugal Regional Operational Programme (ON.2− O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF). This work was also partly funded by FEDER funds through the COMPETE 2020 Programme and National Funds through FCT - Portuguese Foundation for Science and Technology under the project UID/CTM/50025/2013
    corecore