Gender Gaps in different Grading Systems

This paper analyses the impact of grading practices on the gender gap in student achievement. We examine the gender difference in the difference between teacher grading and scores on national exams to test whether there are gender differences associated with different grading systems. We use Portuguese data on 21 subjects across humanities and sciences for the whole population of students taking exams at the end of the 6th, 9th, 11th and 12th grades from 2007 to 2016. Results show that the difference in scores between teacher grading and exams is on average positive for boys and girls, but higher for the latter. This is verified across the whole distribution of exam scores. Thus, our results indicate that a grading system based on exams favors boys while one based on classroom evaluation favors girls.N/

Uma abordagem interdisciplinar entre o bloco de jogos e a matemática do 1.º ciclo do ensino básico

As crianças aprendem através do movimento, da exploração e manipulação de objetos, do brincar e do jogo. Os Jogos, no âmbito e do Programa de Educação Física (EF), podem ser trabalhados de uma forma interdisciplinar com a Matemática proporcionando à criança uma aprendizagem mais enriquecedora, tanto em termos motores como cognitivos. Esta investigação de natureza qualitativa com procedimentos de investigação-ação, teve como ponto de partida a questão: De que forma a vivência de Jogos interdisciplinares com a Matemática influenciará a compreensão dos conteúdos e se lembrarão das ações motoras e dos Jogos praticados nas aulas? O estudo foi desenvolvido com uma turma do 2.º ano, durante o ano letivo 20/21 numa escola do 1.º CEB. Durante três semanas foram operacionalizadas seis sessões de EF e foram lecionadas, em cada semana, uma aula de EF (Jogos) e outra interdisciplinar (Jogos e Matemática). De salientar que as sessões interdisciplinares contemplaram os jogos recriados das sessões EF para incluírem os conteúdos da Matemática. Pela análise dos resultados obtidos observámos que a vivência dos conteúdos matemáticos através dos jogos poderá ter contribuído de uma forma positiva na consolidação dos conceitos matemáticos e que os alunos conseguiram lembrar-se das ações motoras e dos Jogos das aulas

Production and Characterization of k-Carrageenan Films Incorporating Cymbopogon winterianus Essential Oil as New Food Packaging Materials

The global production of synthetic plastics from petroleum-based raw ingredients exceeds 150 million metric tons. The environment is threatened by tons of plastic waste, thus endangering wildlife and the public’s health. These consequences increased the interest in biodegradable polymers as potential substitutes for traditional packaging materials. This study aimed to produce and characterize k-carrageenan films incorporating Cymbopogon winterianus essential oil, in which citronellal was determined to be the major compound (41.12%). This essential oil presented remarkable antioxidant activity, as measured through DPPH (IC50 = 0.06 ± 0.01%, v/v; AAI = 85.60 ± 13.42) and β-carotene bleaching (IC50 = 3.16 ± 0.48%, v/v) methods. The essential oil also showed antibacterial properties against Listeria monocytogenes LMG 16779 (diameter of inhibition zone = 31.67 ± 5.16 mm and MIC = 8 µL/mL), which were also observed when incorporated in the k-carrageenan films. Moreover, scanning electron microscopy showed the reduction of the biofilms of this bacterium, and even its inactivation, due to visible destruction and loss of integrity when the biofilms were created directly on the developed k-carrageenan films. This study also revealed the quorum sensing inhibition potential of Cymbopogon winterianus essential oil (diameter of violacein production inhibition = 10.93 ± 0.81 mm), where it could impede intercellular communication and, hence, lower violacein synthesis. The produced k-carrageenan films were transparent (>90%) and slightly hydrophobic (water contact angle > 90°). This work demonstrated the viability of using Cymbopogon winterianus essential oil to produce k-carrageenan bioactive films as new food packaging materials. Future work should focus on the scale-up production of these films.info:eu-repo/semantics/publishedVersio

Antiviral edible coatings and films: A strategy to ensure food safety

Background Pathological viral transmission via food has been a problem throughout humankind's evolutionary history, impacting food safety and public health. Fresh produce can be contaminated at any stage from pre- to post-harvest and frequently goes through little to no processing, imposing a high risk for contamination by foodborne viruses. Also, due to the globalization of the food industry and supply networks, the spread of enteric virus-related foodborne disorders has worsened. The current understanding of the transmission of viruses through contaminated foods needs more information regarding the potential infectivity, and it is essential to have effective ways to prevent viral transmission and minimize its adverse effects on human and animal health. Scope and approach This review addresses the global public health issue related to foodborne viruses and the current challenges of food safety. It provides an overview of food-grade and naturally occurring antiviral compounds with good antimicrobial activity and emphasizes how edible films and coatings with embedded antiviral agents can reduce the transmission of foodborne illness. Key findings and conclusions Antiviral edible films and coatings can be developed using plant-based compounds and their derived-products, like essential oils and extracts, with bioactive properties. Their use in food products and food contact materials can contribute to developing strategies to contain infectious outbreaks. Results show that these compounds interact with the viral particle, causing some damage to the virus integrity and affecting its infectivity. The development of antiviral edible films and coatings containing these bioactive compounds showed great potential against enteric viruses that cause foodborne illness, specifically norovirus and hepatitis A virus. However, some antiviral agents have also been shown to be very effective against other pathogenic viruses of great importance, some of which are not typically foodborne but can also be dangerous to humans.This work received funding from EIT Food (Grant agreement ID: 20400), the innovation community on Food of the European Institute of Innovation and Technology (EIT), a body of the EU, under Horizon 2020, the EU Framework Programme for Research and Innovation.info:eu-repo/semantics/publishedVersio

Bacterial cellulose/cashew gum films as probiotic carriers

This study was carried out to obtain probiotic films with good stability by combining spore-forming, resistant bacteria (Bacillus coagulans) with a biopolymer mix (bacterial cellulose BC and cashew gum - CG) as a carrier matrix. Fructooligosaccharides (FOS) were used as prebiotic. Four different films were produced, namely, Co (control), Pro (added with probiotic), Pre (containing the prebiotic FOS), and Syn (synbiotic films containing probiotic and FOS). Although the tensile and barrier properties of films have been undermined by probiotic and FOS, those properties have remained within the values needed for food applications. Most films (except Pre) exhibited hydrophobic character (contact angles > 90°). FOS enhanced probiotic viability upon processing. The storage stability of probiotics was very good; even at 37 °C, the viability loss did not surpass 1 log cycle, due to the resistance of B. coagulans and the protective role of BC. Moreover, no cytotoxic effect of the films was observed on Caco-2 cells.The authors gratefully acknowledge the financial support of the Brazilian Agricultural Research Corporation (EMBRAPA, Brazil, 23.14.04.007.00.00 and Rede AgroNano, 0114030010300). the Research Support Foundation of Ceará State (FUNCAP/CNPq PR2-0101-00023.01.00/15), as well as the Coordination for the Improvement of Higher Education Personnel (CAPES) and the Portuguese Foundation for Science and Technology (FCT) on a Brazil/Portugal Bilateral Agreement (CAPES/FCT 99999.008530/2014-09). We also thank Sacco Srl (Italy) for providing us with Bacillus coagulans. Author Oliveira thanks FUNCAP (BMD-0008-0026 3.01.08/17) and CAPES (8887.138002/2017-00) for her scholarship. Author Azeredo thanks the National Council for Scientific and Technological Development (CNPq) for her Research Productivity Fellowship (302381/2016-3).info:eu-repo/semantics/publishedVersio

Resveratrol-loaded octenyl succinic anhydride modified starch emulsions and hydroxypropyl methylcellulose (HPMC) microparticles: Cytotoxicity and antioxidant bioactivity assessment after in vitro digestion

Hydroxypropyl methylcellulose (HPMC)-based microparticles and modified starch emulsions (OSA-MS) were loaded with resveratrol and characterized regarding their physicochemical and thermal properties. Both delivery systems were subject to an in vitro gastrointestinal digestion to assess the bioaccessibility of resveratrol. In addition, cell-based studies were conducted after in vitro digestion and cytotoxicity and oxidative stress were assessed. HPMC-based microparticles displayed higher average sizes (d) and lower polydispersity index (PDI) (d = 948 nm, PDI < 0.2) when compared to OSA-MS-based emulsions (d = 217 nm, PDI < 0.3). Both proved to protect resveratrol under digestive conditions, leading to an increase in bioaccessibility. Resveratrol-loaded HPMC-microparticles showed a higher bioaccessibility (56.7 %) than resveratrol-loaded emulsions (19.7 %). Digested samples were tested in differentiated co-cultures of Caco-2 and HT29-MTX, aiming at assessing cytotoxicity and oxidative stress, and a lack of cytotoxicity was observed for all samples. Results displayed an increasing antioxidant activity, with 1.6-fold and 1.4-fold increases over the antioxidant activity of free resveratrol, for HPMC-microparticles and OSA-MS nanoemulsions, respectively. Our results offer insight into physiological relevancy due to assessment post-digestion and highlight the protection that the use of micro-nano delivery systems can confer to resveratrol and their potential to be used as functional food ingredients capable of providing antioxidant benefits upon consumption.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit, and by LABBELS – Associate Laboratory in Biotechnology, Bioengineering and Microelectromechanical Systems, LA/P/0029/2020 and LAQV/REQUIMTE (UIDB/50006/2020, UIDP/50006/2020). This work was funded by the SbDtoolBox - Nanotechnology-based tools and tests for Safer-by-Design nanomaterials, with the reference NORTE-01-0145-FEDER-000047, funded by Norte 2020 – North-Regional Operational Program under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). The research also received funding from the European Union's H2020 research and innovation program under the Marie Sklodowska-Curie grant agreement N 778388 (H2020 MSCA-RISE-2017 project Food for Diabetes and Cognition (FODIAC), and grant agreement N 713640 (MSCA-2015-COFUND-FP). Pedro Silva is the recipient of a fellowship (SFRD/BD/130247/2017) supported by Fundação para a Ciência e a Tecnologia, (FCT, Portugal). Ana Isabel Bourbon acknowledges funding by FCT, through the individual scientific employment program contract (2020.03447.CEECIND). We also would like to thank the Advanced Electron Microscopy, Imaging, and Spectroscopy (AEMIS) and the Nanophotonics and Bioimaging Facility (NBI) from INL for their support

Avaliação da nanotoxicidade de nanopartículas lipidicas aplicadas na formulação de sistemas de libertação controlada

[Excerto] Tem sido crescente a evidência de que nanopartículas podem induzir toxicidade celular relevante com forte impacto na saúde humana. Esta toxicidade pode ser expressa através da indução de diversas respostas celulares tais como a morte celular, inflamação e stress oxidativo, tornando-se assim de extrema importância a utilização de modelos celulares in vitro para avaliar a resposta biológica desencadeada pela presença dos nanosistemas formulados. O modelo celular Caco-2, utilizado neste trabalho, é um modelo amplamente aceite para avaliação da toxicidade, transporte e uptake de vários materiais à nanoescala. [...]info:eu-repo/semantics/publishedVersio

Low energy nanoemulsions as a carrier of thyme and lemon balm essential oils

The aim of this work was to produce monomodal and stable thyme and lemon balm-loaded nanoemulsions (NE), through a low energy approach. NEs were prepared by the emulsion phase inversion method using sunflower oil as carrier and Tween 80 as surfactant. Different surfactant-to-oil ratios (SOR) and essential oil (EO) loadings were evaluated. Nanoemulsions presented a monomodal diameter distribution below 200 nm and high negative zeta potential (>-40 mV). Nanoemulsions loaded with EOs were physically stable for 3 months at 4 degrees C and 20 degrees C. Nanoemulsions with thyme EO presented the highest radical scavenging activity by DPPH and ABTS tests. Loaded nanoemulsions were not effective against Escherichia coli but could inhibit Staphylococcus aureus. Cytotoxicity studies using cell counting kit-8 and resazurin assays revealed a dose-responsive effect of nanoemulsions on Caco-2 cells after incubation for 24 h. A concentration of 100 mu g oil/mL of NE for unloaded and thyme loaded and 50 mu g oil/mL of NE for lemon balm loaded showed to be safe to use.This research received funding from the H2020 research and inno-vation programme under the Marie Sklodowska-Curie grant agreement No 778388 (H2020 MSCA-RISE-2017, FODIAC) , and MICRODIGEST project (grant agreement 037716) co-funded by FCT and ERDF through COMPETE2020. We would like to thank the Earth Essences for its kind supply of essential oils

Evaluating the effect of chitosan layer on bioaccessibility and cellular uptake of curcumin nanoemulsions

Curcumin nanoemulsions stabilized by whey protein isolate were successfully developed using high-pressure homogenization. The effect of a chitosan layer deposition using the layer-by-layer technique on nanoemulsions' stability was evaluated during storage conditions, as well as during gastrointestinal tract passage. Lipids hydrolysis and curcumin bioaccessibility was assessed using a dynamic gastrointestinal model (simulating the stomach, duodenum, jejunum and ileum) and the cytotoxicity, cellular antioxidant activity and permeability analyses were carried out using Caco-2cells. Results showed that both nanosystems were stable during one month of storage and at stomach pH conditions, whereas creaming and phase separation occurred at intestine pH conditions. The addition of a chitosan layer increased curcumin bioaccessibility, whereas cellular antioxidant activity studies revealed that nanoemulsions and multilayer nanoemulsions exhibited 9 and 10 times higher antioxidant capacity at the cellular level, respectively, when compared to free curcumin. Permeability assays showed that the use of a chitosan layer significantly increased the apparent permeability coefficient of curcumin through Caco-2cells by 1.55-folds.The authors Hélder D. Silva, Ana C. Pinheiro and Miguel A. Cerqueira (SFRH/BD/81288/2011, SFRH/BPD/101181/2014 and SFRH/BPD/72753/2010, respectively) are the recipients of a fellowship from the Foundation for Science and Technology. This work was supported by Portuguese Foundation for Science and Technology under the scope of the Project PTDC/AGR-TEC/5215/2014, of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684), BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte, PEst-OE/EQB/LA0004/2011 and iNOVA4Health - UID/Multi/04462/2013, a program financially supported by FCT/Ministério da Educação e Ciência, through national funds and co-funded by FEDER under the PT2020 Partnership Agreement. The authors also acknowledge the European Commission: BIOCAPS (316265, FP7/REGPOT-2012-2013.1). The support of EU Cost Action FA1001 is gratefully acknowledged. The authors also acknowledge Stepan (The Netherlands) for providing the Neobee 1053 oil, and Rui Fernandes from IBMC, University of Porto for assistance in taking the TEM pictures.info:eu-repo/semantics/publishedVersio

Bacterial cellulose nanofiber-based films incorporating gelatin hydrolysate from tilapia skin: production, characterization and cytotoxicity assessment

In this work, films based on bacterial cellulose nanofibers (BCNFs) incorporating gelatin hydrolysate (GH) from tilapia skin were produced. The effect of plasticizer (sorbitol or glycerol) and GH incorporation was evaluated on the physicalchemical and optical properties of films. BCNFs were produced using bacterial cellulose obtained from Hestrin and Schramm (HS) medium (BCNF-HS) or cashew apple juice (BCNF-CM), which was studied as an alternative to HS. Films with sorbitol showed the best properties and were selected for further characterization, using 40% (w/w) of BCNF-HS, 40% (w/w) of GH and 20% (w/w) of sorbitol (BCNF-HS-S-GH films). These films exhibited an antioxidant activity of 7.8 µmols Trolox Eq/g film, a water vapor permeability (WVP) of 1.6 g.mm/kPa.h.m2 and an Youngs modulus of 0.57 GPa. Films produced with BCNFs obtained from cashew apple juice revealed enhanced tensile strength, elongation at break, and thermal stability. Caco-2 cells viability after incubation with BCNF-based films incorporating GH was evaluated and showed non-cytotoxicity, reinforcing the safety of the developed materials and their potential use in food applications.The authors would like to thank: Foundation of Support to the Scientific and Technological Development (FUNCAP, Brazil), Coordination for the Improvement of Higher Education Personnel (CAPES, Brazil), National Counsel of Technological and Scientific Development (CNPq, Brazil), Minho University (Braga, Portugal) and International Iberian Nanotechnology Laboratory (Braga, Portugal). This work was funded by research projects CNPq n 485465/2012-4, CNPq n 310368/2012-0 and CNPq n 476978/2013-0. Funding from Fundac¸a ˜o para a Cie ˆncia e Tecnologia through the project ‘‘Bacterial Cellulose: a platform for the development of bionanoproducts’’, under the bilateral program FCT/CAPES, is acknowledged. The authors acknowledge also the funding from QREN (‘‘Quadro de Referência Estratégica Nacional’’), ADI (‘‘Agência de Inovação’’) through the project Norte-070202-FEDER-038853, and BioTecNorte operation (NORTE01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020—Programa Operacional Regional do Norte. This research was supported by Norte Regional Operational Program 2014–2020 (Norte2020) through the European Regional Development Fund (ERDF) Nanotechnology based functional solutions (NORTE-01-0145FEDER-000019).info:eu-repo/semantics/publishedVersio