Suchergebnisse

Dissertação de Mestrado em Segurança Alimentar apresentada à Faculdade de Farmácia ; The consumption of pistachios (Pistacia vera L.) has been increasing, given its important benefit in human health. In addition to an excellent nutritional source, it has associated chemical hazards, such as mycotoxins, resulting of fungal contamination and its secondary metabolism. Pistachios are one of nuts with higher mycotoxin's contamination worldwide, especially Aflatoxin B1 with a hepatotoxic effect and classified as proven carcinogenic to humans by the International Agency for Research on Cancer (IARC). More mycotoxins as ochratoxin A (OTA), fumonisins (FBs), zearalenone (ZEA) and trichothecenes (T2, HT2 and DON) and emerging mycotoxins have been concerned in nuts. This study developed a Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method followed by Ultra-High Performance Liquid Chromatography combined with Time-of-Flight Mass Spectrometry (UHPLC–ToF-MS) for the determination of multi-mycotoxins in pistachios.Different approaches in dispersive solid phase extraction (d-SPE) as clean-up for high-lipid matrix were to evaluate. For this, classic sorbents, like C18 (octadecyl modified silica) and PSA (primary secondary amine) and new classes of sorbents, namely EMR-Lipid (enhanced matrix removal-lipid) and Z-Sep (modified silica gel with zirconium oxide) are used. Method with 100 mg Z-Sep sorbent provided the best analytical performance, with good recovery (79 to 120%), repeatability (RSDr<10%) and precision inter-day (RSDR<10%) in agreement with criteria established by Commission Regulation EC No. 401/2006 for mycotoxins analysis. The method was validated for aflatoxins (AFB1, AFB2, AFG1 and AFG2), ochratoxin A (OTA), zearalenone (ZEA), toxin T2 (T2) and toxin HT-2 (HT2). The LODs for AFs ranged from 0.125 to 0.25 ug/Kg, which are lower than the maximum levels in nuts regulated by the EU. The method was applied to 16 real pistachio samples and 6 of these presented one mycotoxin (AFB1, HT2 or FB1) but at low concentrations. The concentration of AFB1 was lower than the maximum permitted level established by the EU legislation. Also, AFB2 and FB1 are detected in pistachio shells. In this line, pistachios samples selected in the present study and available in the Portuguese market are safe for human consumption concerning mycotoxins content. ; O consumo de pistácios (Pistacia vera L.) tem vindo a aumentar devido ao seu reconhecido benefício na saúde humana. Apesar de constituírem uma excelente fonte nutricional, os pistácios têm riscos químicos associados, como as micotoxinas, resultantes da contaminação de fungos e do seu metabolismo secundário. Os pistácios são um dos frutos secos com maior contaminação por micotoxinas em todo o mundo, especialmente por aflatoxinas. As aflatoxinas são as mais tóxicas para os seres humanos, particularmente a aflatoxina B1 com efeito hepatotóxico e classificada como comprovadamente carcinogénica para o homem pela Agência Internacional para a Investigação do Cancro (IARC). Outras micotoxinas são relevantes como ocratoxina A (OTA), fumonisinas (FBs), zearalenone (ZEA) e trichotecenes (T2, HT2 e DON) e mais recentemente, as micotoxinas emergentes.Este estudo desenvolveu um método rápido, fácil, barato, eficaz, robusto e seguro (QuEChERS) seguido de Cromatografia Líquida de Ultra Resolução combinada com Espectrometria de Massa de Tempo de Voo (UHPLC-ToF-MS) para a determinação das micotoxinas em pistácios. Diferentes abordagens no clean-up pela técnica de extração de Fase Sólida Dispersiva (d-SPE) foram avaliadas. Para isso, foram utilizados adsorventes clássicos, como C18 (octadecil sílica) e PSA (amina secundária primária) e novas classes de adsorventes, nomeadamente, EMR-Lipid (enhanced matrix removal-lipid) e Z-Sep (gel de sílica modificada com óxido de zircónio). O método com 100 mg de Z-Sep proporcionou o melhor desempenho analítico, com uma boa recuperação (79 a 120%), boa repetibilidade (RSDr<10%) e a boa precisão inter-dia (RSDR<10%) de acordo com critérios estabelecidos pelo Regulamento N.º 401/2006 da Comissão Europeia para a análise das micotoxinas. O método foi validado para aflatoxinas (AFB1, AFB2, AFG1 e AFG2), ocratoxina A (OTA), zearalenona (ZEA), toxina T2 (T2) e toxina HT-2 (HT2). Os LODs para as AFs variaram entre 0,125 e 0,25 ug/Kg, concentrações inferiores aos níveis máximos para frutos secos regulados pela UE. O método foi aplicado a 16 amostras de pistácios e em 6 destas foi determinada uma micotoxina (AFB1, HT2 ou FB1), mas em baixas concentrações. A concentração de AFB1 foi inferior ao valor máximo permitido de acordo com a legislação da União Europeia. Além disso, AFB2 e FB1 foram detetadas nas cascas de pistácios. Assim, os pistácios selecionados para o presente estudo e disponíveis no mercado português são considerados seguros para o consumo humano no que diz respeito à presença de micotoxinas. ; FCT

Dissertação de Mestrado em Segurança Alimentar apresentada à Faculdade de Farmácia ; The consumption of pistachios (Pistacia vera L.) has been increasing, given its important benefit in human health. In addition to an excellent nutritional source, it has associated chemical hazards, such as mycotoxins, resulting of fungal contamination and its secondary metabolism. Pistachios are one of nuts with higher mycotoxin's contamination worldwide, especially Aflatoxin B1 with a hepatotoxic effect and classified as proven carcinogenic to humans by the International Agency for Research on Cancer (IARC). More mycotoxins as ochratoxin A (OTA), fumonisins (FBs), zearalenone (ZEA) and trichothecenes (T2, HT2 and DON) and emerging mycotoxins have been concerned in nuts. This study developed a Quick, Easy, Cheap, Effective, Rugged, and Safe (QuEChERS) method followed by Ultra-High Performance Liquid Chromatography combined with Time-of-Flight Mass Spectrometry (UHPLC–ToF-MS) for the determination of multi-mycotoxins in pistachios.Different approaches in dispersive solid phase extraction (d-SPE) as clean-up for high-lipid matrix were to evaluate. For this, classic sorbents, like C18 (octadecyl modified silica) and PSA (primary secondary amine) and new classes of sorbents, namely EMR-Lipid (enhanced matrix removal-lipid) and Z-Sep (modified silica gel with zirconium oxide) are used. Method with 100 mg Z-Sep sorbent provided the best analytical performance, with good recovery (79 to 120%), repeatability (RSDr<10%) and precision inter-day (RSDR<10%) in agreement with criteria established by Commission Regulation EC No. 401/2006 for mycotoxins analysis. The method was validated for aflatoxins (AFB1, AFB2, AFG1 and AFG2), ochratoxin A (OTA), zearalenone (ZEA), toxin T2 (T2) and toxin HT-2 (HT2). The LODs for AFs ranged from 0.125 to 0.25 ug/Kg, which are lower than the maximum levels in nuts regulated by the EU. The method was applied to 16 real pistachio samples and 6 of these presented one mycotoxin (AFB1, HT2 or FB1) but at low concentrations. The concentration of AFB1 was lower than the maximum permitted level established by the EU legislation. Also, AFB2 and FB1 are detected in pistachio shells. In this line, pistachios samples selected in the present study and available in the Portuguese market are safe for human consumption concerning mycotoxins content. ; O consumo de pistácios (Pistacia vera L.) tem vindo a aumentar devido ao seu reconhecido benefício na saúde humana. Apesar de constituírem uma excelente fonte nutricional, os pistácios têm riscos químicos associados, como as micotoxinas, resultantes da contaminação de fungos e do seu metabolismo secundário. Os pistácios são um dos frutos secos com maior contaminação por micotoxinas em todo o mundo, especialmente por aflatoxinas. As aflatoxinas são as mais tóxicas para os seres humanos, particularmente a aflatoxina B1 com efeito hepatotóxico e classificada como comprovadamente carcinogénica para o homem pela Agência Internacional para a Investigação do Cancro (IARC). Outras micotoxinas são relevantes como ocratoxina A (OTA), fumonisinas (FBs), zearalenone (ZEA) e trichotecenes (T2, HT2 e DON) e mais recentemente, as micotoxinas emergentes.Este estudo desenvolveu um método rápido, fácil, barato, eficaz, robusto e seguro (QuEChERS) seguido de Cromatografia Líquida de Ultra Resolução combinada com Espectrometria de Massa de Tempo de Voo (UHPLC-ToF-MS) para a determinação das micotoxinas em pistácios. Diferentes abordagens no clean-up pela técnica de extração de Fase Sólida Dispersiva (d-SPE) foram avaliadas. Para isso, foram utilizados adsorventes clássicos, como C18 (octadecil sílica) e PSA (amina secundária primária) e novas classes de adsorventes, nomeadamente, EMR-Lipid (enhanced matrix removal-lipid) e Z-Sep (gel de sílica modificada com óxido de zircónio). O método com 100 mg de Z-Sep proporcionou o melhor desempenho analítico, com uma boa recuperação (79 a 120%), boa repetibilidade (RSDr<10%) e a boa precisão inter-dia (RSDR<10%) de acordo com critérios estabelecidos pelo Regulamento N.º 401/2006 da Comissão Europeia para a análise das micotoxinas. O método foi validado para aflatoxinas (AFB1, AFB2, AFG1 e AFG2), ocratoxina A (OTA), zearalenona (ZEA), toxina T2 (T2) e toxina HT-2 (HT2). Os LODs para as AFs variaram entre 0,125 e 0,25 ug/Kg, concentrações inferiores aos níveis máximos para frutos secos regulados pela UE. O método foi aplicado a 16 amostras de pistácios e em 6 destas foi determinada uma micotoxina (AFB1, HT2 ou FB1), mas em baixas concentrações. A concentração de AFB1 foi inferior ao valor máximo permitido de acordo com a legislação da União Europeia. Além disso, AFB2 e FB1 foram detetadas nas cascas de pistácios. Assim, os pistácios selecionados para o presente estudo e disponíveis no mercado português são considerados seguros para o consumo humano no que diz respeito à presença de micotoxinas. ; FCT

El presente documento se propone reconocer el lesbianismo feminista como una producción discursiva, inserta en relaciones de poder y agenciamientos que operan de modo evidente en sus discursos 'oficiales' y desde sus voces autorizadas. Se realizará un análisis crítico de una selección de distintos discursos, producidos por voces autorizadas del lesbianismo feminista latinoamericano y del Caribe, con la intención de develar cómo desde estos discursos, la experiencia y los cuerpos trans se han constituido en el 'afuera' del lesbianismo feminista. Esto es como límite de lo posible, imaginable y deseable al interior del Encuentro Lésbico Feminista de América Latina y el Caribe (ELFLAC) que se realiza anualmente. Finalmente, el artículo se enfocará en las propuestas del Encuentro LesBiTransInter Feminista: Venir al Sur, en torno a los actuales sujetos y cuerpos de los feminismos.

Antimicrobial resistance (AMR) has recently emerged as a salient global issue, and policy formulation to address AMR has become a contested space, with various actors sharing competing-and sometimes contradictory-explanations of the problem and the range of possible solutions. To facilitate national policy setting and implementation around AMR, more needs to be done to effectively engage policymakers in low- and middle-income countries (LMICs). However, there is a dearth of research on differences in issue framing by external agencies and LMIC's national policymakers on the problem of AMR; such analyses are imperative to identify areas of conflict and/or potential convergence. We compared representations of AMR across nine policy documents produced by multilateral agencies, donor countries and an LMIC at the forefront of the global response to AMR-Pakistan. We analysed the texts in relation to five narratives that have been commonly used to frame health issues as requiring action: economic impact, stunting of human development, consequences for health equity, health security threats and relationship with food production. We found that AMR was most frequently framed as a threat to human health security and economic progress, with several US, UK and international documents depicting LMICs as 'hotspots' for AMR. Human development and equity dimensions of the problem were less frequently discussed as reasons to address the growing burden of AMR. It is clear that no single coherent narrative on AMR has emerged, with notable differences in framing in Pakistani and external agency led documents, as well as across stakeholders primarily working on human vs animal health. While framing AMR as a threat to economic growth and human security has achieved high-level political attention and catalysed action from governments in high-income countries, our analysis suggests that conflicting narratives relevant to policymakers in Pakistan may affect policy-making and impede the development and implementation of integrated initiatives needed to tackle AMR.

This study aimed to characterize the molecules involved in osteogenesis in seabream and establish using in vitro/in vivo approaches the responsiveness of selected key genes to temperature. The impact of a temperature drop from 23 to 13 degrees C was evaluated in juvenile fish thermally imprinted during embryogenesis. Both, in vitro/in vivo, Fib1a, appeared important in the first stages of bone formation, and Col1A1, ON and OP, in regulating matrix production and mineralization. OCN mRNA levels were up-regulated in the final larval stages when mineralization was more intense. Moreover, temperature-dependent differential gene expression was observed, with lower transcript levels in the larvae at 18 degrees C relative to those at 22 degrees C, suggesting bone formation was enhanced in the latter group. Results revealed that thermal imprinting affected the long-term regulation of osteogenesis. Specifically, juveniles under the low and low-to-high-temperature regimes had reduced levels of OCN when challenged, indicative of impaired bone development. In contrast, gene expression in fish from the high and high-to-low-temperature treatments was unchanged, suggesting imprinting may have a protective effect. Overall, the present study revealed that thermal imprinting modulates bone development in seabream larvae, and demonstrated the utility of the in vitro MSC culture as a reliable tool to investigate fish osteogenesis. ; "Ministerio de Economia y Competitividad" (MINECO) [BES-2015-074654]; Portuguese Science Foundation (FCT) [SFRH/BPD/111512/2015, SFRH/BD/81625/2011]; MINECO, Spain [AGL2010-17324, AGL2014-57974-R]; "Generalitat de Catalunya" (XRAq); Generalitat de Catalunya [2014SGR-01371]; FCT, Portugal [CCMAR/Multi/04326/2013]; European Union [LIFECYCLE EU-FP7 222719] ; info:eu-repo/semantics/publishedVersion

The conditional expression of alternative life strategies is a widespread feature of animal life and a pivotal adaptation to life in seasonal environments. To optimally match suites of traits to seasonally changing ecological opportunities, animals living in seasonal environments need mechanisms linking information on environmental quality to resource allocation decisions. The butterfly Bicyclus anynana expresses alternative adult life histories in the alternating wet and dry seasons of its habitat as endpoints of divergent developmental pathways triggered by seasonal variation in preadult temperature. Pupal ecdysteroid hormone titers are correlated with the seasonal environment, but whether they play a functional role in coordinating the coupling of adult traits in the alternative life histories is unknown. Here, we show that manipulating pupal ecdysteroid levels is sufficient to mimic in direction and magnitude the shifts in adult reproductive resource allocation normally induced by seasonal temperature. Crucially, this allocation shift is accompanied by changes in ecologically relevant traits, including timing of reproduction, life span, and starvation resistance. Together, our results support a functional role for ecdysteroids during development in mediating strategic reproductive investment decisions in response to predictive indicators of environmental quality. This study provides a physiological mechanism for adaptive developmental plasticity, allowing organisms to cope with variable environments. ; European Union's FP6 Programme (Network of Excellence LifeSpan FP6/036894), FCT fellowship (SFRH/BD/45486/2008).