4,844 research outputs found
Stated belief and play in normal form games
Using data on one-shot games, we investigate the assumption that players respond to
underlying expectations about their opponent�s behavior. In our laboratory experiments, subjects
play a set of 14 two-person 3x3 games, and state first order beliefs about their opponent�s
behavior. The sets of responses in the two tasks are largely inconsistent. Rather, we find
evidence that the subjects perceive the games differently when they (i) choose actions, and (ii)
state beliefs � they appear to pay more attention to the opponent�s incentives when they state
beliefs than when they play the games. On average, they fail to best respond to their own stated
beliefs in almost half of the games. The inconsistency is confirmed by estimates of a unified
statistical model that jointly uses the actions and the belief statements. There, we can control for
noise, and formulate a statistical test that rejects consistency. Effects of the belief elicitation
procedure on subsequent actions are mostly insignificant
Beliefs and actions in the trust game: creating instrumental variables to estimate the causal effect
In many economic contexts, an elusive variable of interest is the agent's expectation about relevant events, e.g. about other agents' behavior. Recent experimental studies as well as surveys have asked participants to state their beliefs explicitly, but little is known about the causal relation between beliefs and other behavioral variables. This paper discusses the possibility of creating exogenous instrumental variables for belief statements, by shifting the probabilities of the relevant events. We conduct trust game experiments where the amount sent back by
the second player (trustee) is exogenously varied by a random process, in a way that informs only the �first player (trustor) about the realized variation. The procedure
allows detecting causal links from beliefs to actions under plausible assumptions.
The IV estimates indicate a signi�ficant causal effect, comparable to the connection
between beliefs and actions that is suggested by OLS analyses
Microcassiope minor (Dana, 1852): a description of the first stage zoea (Crustacea: Decapoda: Brachyura: Xanthidae)
The first stage zoea of Microcassiope minor (Dana, 1852) is described, illustrated and compared with thirteen other known Xanthinae. This comparison suggests that M. minor is closely related to another Atlantic Ocean xanthid, Nanocassiope melanodactyla (A. Milne-Edwards, 1867). Such an affinity may indicate that the genus Nanocassiope Guinot, 1967) is not a homogenous taxon
Relevância da informação nutricional para avaliação de risco em saúde pública: o caso do fast-food
Introdução: Com a entrada em vigor do Regulamento (UE) n.º 1169/2011, a declaração nutricional passou a ser obrigatória a partir de 13 de dezembro de 2016 para alimentos pré-embalados. Muitas vezes os fast-food não são pré-embalados e a declaração nutricional não é obrigatória. Em Portugal, de acordo com os resultados do INSEF, a prevalência estimada de hipertensão arterial é 36,0% e de obesidade e excesso de peso de 28,9% e 28,7%, respetivamente.
Objetivos: Determinar o teor de sal, gordura total e ácidos gordos saturados (AGS). Analisar a relevância da informação nutricional na avaliação de risco em saúde pública, avaliando o contributo de uma unidade destes alimentos para as doses diárias de referência (DDR) de sal, gordura total e AGS.
Materiais e métodos: Entre 2015 e 2016 foram adquiridos em restaurantes fast-food, 20 tipos de alimentos que incluíram pizzas (n=8), hambúrgueres (n=8) e baguetes (n=4). O teor de sal foi determinado pelo método de Charpentier-Volhard e o teor de gordura total foi determinado por um método de hidrólise ácida seguido de extração em Soxhlet. Para a análise do perfil de ácidos gordos individual foi aplicada uma transesterificação a frio seguida da análise por cromatografia gasosa acoplada a deteção por ionização de chama.
Resultados e discussão: Verificou-se que uma fatia de pizza (amostra G) pode contribuir com 81% da ingestão diária recomendada de sal (5 g/dia para adultos). No caso das crianças a DDR é de 2,5 g de sal/dia o que significa que a ingestão de uma unidade deste produto ultrapassa o valor recomendado. Relativamente ao teor de gordura total, uma unidade de hambúrguer (amostra F) pode contribuir com 74% da DDR para um adulto (70 g/dia para adultos).
Conclusões: Alguns dos fast-food analisados apresentam teores preocupantes de determinados nutrientes, podendo representar um risco acrescido para a saúde. Desta forma conclui-se que é muito importante incluir a declaração nutricional, de forma obrigatória, mesmo nos alimentos que não são pré-embalados para possibilitar ao consumidor uma escolha informada e consciente; e também é necessário desenvolver medidas no sentido de reformular estes produtos para melhorar a sua qualidade nutricional e diminuir o impacto negativo na saúde pública.Este trabalho foi financiado pelo INSA, no âmbito do projeto PTranSALT (2012DAN828). Tânia Gonçalves Albuquerque agradece a Bolsa de Doutoramento (SFRH/BD/99718/2014) financiada pela FCT, FSE e MEC.N/
Application of an HPLC method for the quality control of vitamin C content in foods for infants
Vitamin C is an important water-soluble vitamin that humans are not able to synthesize, so it needs to be provided by the diet. Babies less than 1 year usually do not eat foods naturally rich in vitamin C, so the main sources are breast milk and/or infant formulas. Regulation (EU) No. 609/2013, Commission Delegated Regulation (EU) No. 2016/127 and Ministério da Agricultura, do Desenvolvimento Rural e das Pescas (2008) establishes compositional and information requirements for food intended for infants and young children [1-3]. Adequate intake of vitamin C is very important to assure children’s good health and development, so it is crucial to evaluate vitamin C content in this type of foods.
The aim of this study was to validate a high-performance liquid chromatography (HPLC) method for the quality control of vitamin C content in infant foods (2 infant formulae (IF), 2 follow-on formulae (FF), 2 processed cereal-based foods (PCF) and 2 baby foods (BF)).
In 2016, the infant foods were collected from major supermarket chains and parapharmacies in the region of Lisbon (Portugal). Two of the acquired samples were already ready-to-use, while the remaining samples were prepared according to manufacturer’s instructions. Separation and quantification of vitamin C was carried out on an Alliance 2695 HPLC system, with diode array detection (DAD), using a SynergiTM Hydro-RP analytical column (150 x 4.6 mm I.D., 4.0 μm particle size). Samples were monitored at 245 nm.
The HPLC-DAD analytical method was validated for selectivity, linearity, LOD, LOQ, precision and accuracy, using an infant formula. Calibration curves were linear over the range 1-100 µg/mL. The achieved LOD and LOQ were 0.026 and 0.086 µg/mL, respectively. Vitamin C content in the analysed samples ranged from 1.5 ± 0.01 to 178 ± 1.01 mg/100 g for BF1 and PCF2, respectively.
The developed method is rapid, specific, precise and accurate, for the quantification of vitamin C in different categories of foods for infants and young children, showing satisfactory data for all the tested parameters. Since this type of food products are very important for such young and vulnerable consumers, regulation and assurance of an adequate intake of essential nutrients, like vitamin C, is extremely important for a healthy development.
References:
[1] European Parliament/Council of the European Union. (2013). Regulation (EU) No 609/2013 of the European Parliament and of the Council of 12 June 2013 on food intended for infants and young children, food for special medical purposes, and total diet replacement for weight control. Official Journal of the European Union, L181, 35-56.
[2] European Commission. (2016). Commission Delegated Regulation (EU) 2016/127 of 25 September 2015 supplementing Regulation (EU) No 609/2013 of the European Parliament and of the Council as regards the specific compositional and information requirements for infant formula and follow-on formula. Official Journal of the European Union, L25, 1-29.
[3] Ministério da Agricultura, do Desenvolvimento Rural e das Pescas (2008). Decreto-Lei n.º 53/2008 de 25 de Março. Diário da República, 1ª série - Nº 59, 1667-1674.This work was funded by INSA under the project “BIOCOMP” (2012DAN730). Tânia Gonçalves Albuquerque acknowledges the PhD fellowship (SFRH/BD/99718/2014) funded by the FCT, FSE and MEC.N/
Cream crackers vs. “Maria” cookies: Which are the main differences?
Introduction: Cookies are widely consumed especially by young people. Nowadays there is a wide range of this type of products, and every day new options are available in the market. These foodstuffs are generally recognized as a source of unhealthy nutrients, such as salt and fat, namely saturated and trans fatty acids. The excessive intake of those nutrients is linked with an enhanced risk for the development of several chronic diseases.
Aim: To determine salt, total fat and fatty acids composition of “Maria” cookies and cream crackers, as well as to estimate the benefit/risk associated with their consumption.
Materials and methods: In 2016, 8 brands of cream crackers and 7 brands of “Maria” cookies widely distributed in the Portuguese market were selected to analyse the salt and fat contents and fatty acids composition. Sampling includes the main representative cookie brands, but also commercial and supermarket brands.
Results and conclusions: For cream crackers the total fat content varied between 10.3 and 23.0 g/100 g, while for “Maria” cookies it ranged from 8.73 to 19.5 g/100 g. Concerning salt content, cream crackers have the highest value (1.82 g/100 g). The saturated fatty acids were the major in 6 cream cracker brands and in 4 “Maria” cookies brands. Trans fatty acids ranged from 29.2 to 82.4 mg/100 g (cream crackers) and from 24.5 to 73.2 mg/100 g (“Maria” cookies). The main difference between the studied groups was the salt content. Therefore, the reformulation of these foodstuffs is very important in order to produce healthier foods.This work was funded by INSA under the project “PTranSALT” (2012DAN828). Tânia Gonçalves Albuquerque acknowledges the PhD fellowship (SFRH/BD/99718/2014) funded by the FCT, FSE and MEC.N/
Avaliação dos teores de fenólicos e flavonóides totais em frutos
Os frutos, em particular os frutos vermelhos, têm vindo a suscitar um interesse crescente entre os consumidores devido às propriedades nutricionais que apresentam. Constituem uma fonte natural de antioxidantes, compostos bioativos e vitaminas, e o seu consumo está associado à diminuição dos fatores de risco para diversas doenças. O objetivo deste trabalho foi determinar o teor de compostos fenólicos e flavonóides totais em frutos.
Em 2016 foram adquiridos em grandes superfícies da região de Lisboa 14 tipos de frutos. O teor de compostos fenólicos totais foi determinado pelo método Folin-Ciocalteu, sendo os resultados expressos em equivalentes de ácido gálhico (EAG) e o teor de flavonóides totais foi expresso em equivalentes de epicatequina (EEC).
De acordo com os resultados obtidos, os mirtilos foram a amostra que apresentou maior teor de compostos fenólicos totais e de flavonóides totais, 1,29 ± 0,0 mg EAG/mL e 164 ± 10,4 µg EEC/mL, respetivamente. Por outro lado, o pêssego foi a amostra que apresentou o menor valor para os dois métodos, 0,187 ± 0,0 mg EAG/mL para os fenólicos totais e 11,5 ± 0,4 µg EEC/mL para os flavonóides totais.
Tendo por base os resultados obtidos, é possível concluir que os frutos vermelhos analisados (mirtilos, framboesas e morangos) apresentaram maior teor de compostos fenólicos e flavonóides totais, quando comparados com as restantes amostras analisadas.Este trabalho foi financiado pelo INSA no âmbito do projeto BioCOMP (2012DAN730). Tânia Gonçalves Albuquerque agradece a Bolsa de Doutoramento (SFRH/BD/99718/2014) financiada por FCT, FSE e MEC.info:eu-repo/semantics/publishedVersio
4-Hydroxynonenal: a parameter of quality and safety of vegetable oils
EC Nutrition Editor’s Column - 2017Due to several factors, namely social, economic and technical, people have less time to spend in food preparation. Consequently, the consumption of fried and pre-fried foods has been increasing due to its easy preparation. This behaviour has been linked to an increase in the intake of fats and oils subjected to high temperatures. Oils and fats are previously processed (refining) to improve their quality, stability and safety. Despite the removal of a large amount of impurities from the oil that influence negatively their quality, some processing conditions can often originate new compounds with additional health hazards.This work was funded by National Institute of Health Dr. Ricardo Jorge, I.P., under the project “PTranSALT (2012DAN828)” and by the project “Operação NORTE01-0145-FEDER-000011 - denominada Qualidade e Segurança Alimentar - uma abordagem (nano)tecnológica” and the project UID/QUI/50006/2013 - POCI/01/0145/FEDER/007265 with financial support from FCT/MEC through national funds and co-financed by FEDER. Tânia Gonçalves Albuquerque is grateful for the PhD fellowship (SFRH/ BD/99718/2014) funded by the FCT, FSE and MEC.info:eu-repo/semantics/publishedVersio
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