Fernando Aguilar - Academia.edu (original) (raw)

Papers by Fernando Aguilar

EFSA Journal, Oct 1, 2008

The Panel considered the toxicity studies and the studies on the metabolism of coumarin in humans... more The Panel considered the toxicity studies and the studies on the metabolism of coumarin in humans with CYP2A6 polymorphism that have become available since the last opinion of 2004, as well as clinical studies, and concluded to maintain the TDI of 0.1 mg coumarin/kg bw allocated in the 2004 opinion. Considering the toxicity data on coumarin, including the timing of the onset of liver effects, recovery of these effects after cessation of exposure to coumarin and the elimination half-life, the Panel concluded that exposure to coumarin resulting in an intake 3 times higher than the TDI for one to two weeks is not of safety concern.

EFSA Journal, 2008

Assessment of the results of the study by McCann et al. (2007) on the effect of some colours and ... more Assessment of the results of the study by McCann et al. (2007) on the effect of some colours and sodium benzoate on children's behaviour 1

Laboratory experiences are closely related to student-centred learning strategies. This practical... more Laboratory experiences are closely related to student-centred learning strategies. This practical teaching can be enhanced with the simulation of the real equipment previously used by the students at the laboratory. The usefulness of simulation rely on its element of interaction, and this is broadly characterised as student engagement, which is taken to mean interaction with the simulation with the aim of acquiring or improving understanding. This engaged learning arises from the meaningful nature of the task and is authentic in the sense that it mirrors 'real-life' situations. Three facets of authenticity are the credibility of the simulation, its complexity and whether or not the student has internalised the task. This last feature depends very much on the student's prior experience of the practical situation being simulated. A study and revision of the characteristics of simulations that support learning is presented: the attributes, qualities and circumstances of the...

El presente artículo muestra, a través del desarrollo de una investigación sobre derechos humanos... more El presente artículo muestra, a través del desarrollo de una investigación sobre derechos humanos en la labor de policía judicial 3 , la posibilidad real del uso de un enfoque metodológico mixto, es decir, de la integración de metodologías cuantitativas y cualitativas. En la ciencia social moderna la tensión entre determinar de la manera lo más precisa posible las relaciones entre los fenómenos y comprender en profundidad el sentido de la realidad, ha sido un hecho común a la hora de abordar los fundamentos epistemológicos del conocimiento científico o de diseñar una investigación empírica. Ciertamente que esta tensión es el reflejo de importantes diferencias epistemológicas y ontológicas entre una aproximación cuantitativa y una cualitativa. Salgado (2007) sostiene que Durante el desarrollo de la ciencia, han surgido diversas corrientes de pensamiento, así como diferentes marcos interpretativos, que han originado diferentes rutas en la búsqueda 1 Ponencia en el Cátedra de Investiga...

SUMMARY The Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in Con... more SUMMARY The Scientific Panel on Food Additives, Flavourings, Processing Aids and Materials in Contact with Food (the Panel) is asked to advise the Commission on the implications for human health of chemically defined flavouring substances used in or on foodstuffs in the Member States. In particular the Scientific Panel is requested to consider the Joint FAO/WHO Expert Committee on Food

Technologies for Detection of DNA Damage and Mutations, 1996

Mutational spectrum analysis of DNA has gained considerable interest among molecular toxicologist... more Mutational spectrum analysis of DNA has gained considerable interest among molecular toxicologists as an attempt to correlate DNA alterations caused by endogenous and exogenous mutagens with epidemiological studies of cancer risk factors (Shields and Harris, 1991). Mutational abnormalities in cancer-related genes may suggest mechanisms of carcinogenesis in specific organs or tissues. Furthermore, mutations in proto-oncogenes and tumor suppressor genes in premalignant tissues may become a useful parameter for risk assessment (Greenblatt et al., 1994; Harris, 1993).

Journal of Consumer Studies and Home Economics, 1992

Following a review of the history and organization of farmers' markets in Costa Rica, a compariso... more Following a review of the history and organization of farmers' markets in Costa Rica, a comparison was made of prices offered to consumers at farmers' markets, produce markets and supermarkets in Costa Rica. Findings reveal there are substantial price savings to Costa Rican consumers that shop at local farmers' markets for fruit and vegetables compared to produce markets and supermarkets.

The Journal of Chemical Thermodynamics, 2011

This work reports new experimental density data (445 points) for binary mixtures of (dibutyl ethe... more This work reports new experimental density data (445 points) for binary mixtures of (dibutyl ether + 1butanol) over the composition range (five compositions; 0.15 6 dibutyl ether mole fraction x 6 0.85), from (293.15 to 393.15) K (every 20 K), and for 15 pressures from (0.1 to 140) MPa (every 10 MPa). An Anton Paar vibrating tube densimeter, calibrated with an uncertainty of ±0.5 kg Á m À3 was used to perform these measurements. The experimental density data were fitted with a Tait-like equation with low standard deviations. Excess volumes have been calculated from the experimental data and fitted by the Redlich-Kister equation. In addition, the isobaric thermal expansivity and the isothermal compressibility have been derived from the Tait-like equation.

Journal of Consumer Studies and Home Economics, 1993

The purpose of this study is to determine the effect of Hispanic consumer acculturation on concer... more The purpose of this study is to determine the effect of Hispanic consumer acculturation on concerns about food safety and pesticide residues, and attitudes to ward pesticiderelated agricultural practices. Two 3-min bilingual, English and Spanish, videos presenting information on integrated pest management (IPM) farming practices were shown in controlled settings to Californian Hispanic consumers (n = 91). Findings reveal that acculturation among Hispanic consumers, language of use and length of residency in the United States, are significant factors associated with consumer concerns about the safety of domestic grown and imported produce at the supermarket. Overall, however the research suggests a substantial lack of information by Hispanic consumers regardless of level of acculturation. Pre-and post-video survey results show significant change in attitude among Hispanic consumers toward food safety, farming practices, and university efforts to help farmers control pests and assist with other management techniques. These findings suggest that bilingual educational programmes on food safety and the use of pesticides by farmers would be appropriate.

Journal of Technology and Science Education, 2013

The learning and development of teamwork skill is only possible if its achievement is a self-buil... more The learning and development of teamwork skill is only possible if its achievement is a self-building process of the student. In turn, the teachers must become guides in the process of a learning which is not limited only to the topic of their own course, but which must be imbedded with a good dose of this skill. Promotion of teamwork is not spontaneous but very ofen requires the use of self-regulation within teams. The aim of the paper is to elucidate if positive or negative self-regulation of teams are useful to promote teamwork. The paper presents some experiences on the use of self-regulation of teams within active teaching strategies that involve teamwork as a critical skill in engineering education. The paper presents first the fundamentals of the learning strategy adopted, intended to develop teamwork abilities in the students. It then describes the context and challenges faced up in the case studies, as well as the essentials of the learning activities proposed. Finally, the paper discusses the student's achievement and perception. Although some infuence of unbalanced teams there exists, it can be stated that positive self-regulation of teams is more easily accepted by teams than the negative ones, because of the infuence on interpersonal relationships amongst students. The topics involved in this experience are energy related topics such as electrical installations, heat transfer, engineering thermodynamics or theory of circuits.

Plant Molecular Biology, 1991

A cDNA and a genomic DNA library from soybean (Glycine max L.) were used to identify and sequence... more A cDNA and a genomic DNA library from soybean (Glycine max L.) were used to identify and sequence two genes coding for the e-subunit of the translation elongation factor eEF-1. Within the coding part, the two genes (tefS1 and tefS2) diverge in 80 wobble positions thus yielding an identical protein composed of 447 amino acids. The soybean protein has about 95~o similarity with eEF-le proteins of Arabidopsis thaliana and tomato. Both genes 1and1 and 1and2 contain, within the coding part at a site seemingly unique to higher plants, a single short intron of 86 and 116 nucleotides, respectively. The untranslated leader part of both genes is interrupted by a large intron (partially sequenced). Genes 1and1 and 1and2 are transcribed in young leaves, cDNA and gene-specific oligonucleotide probes interact with a unique transcript of close to 1.9 kb. Northern hybridization studies using RNAs from dark-and light-grown seedlings show that light sharply increases the level of stable transcripts (1.9 kb). A peak value is measured after about 3 h of illumination, afterwards the transcript concentration drops to about 10~o of the peak value. Genes 1and1 and 1and2 follow a similar transcription pattern in developing seedling leaves, which is distinct from that of the rbcS genes measured in parallel experiments. According to northern results, 1transcriptsaremoreabundantinleavesatallmeasuredstagesofdevelopmentthan1 transcripts are more abundant in leaves at all measured stages of development than 1transcriptsaremoreabundantinleavesatallmeasuredstagesofdevelopmentthan2 transcripts.

Flavouring Group Evaluation 62 (FGE.62) Consideration of linear and branched-chain aliphatic unsa... more Flavouring Group Evaluation 62 (FGE.62) Consideration of linear and branched-chain aliphatic unsaturated, unconjugated alcohols, aldehydes, acids, and related esters evaluated by JECFA (61st meeting) structurally related to esters of branched-and straight-chain aliphatic saturated primary alcohols and of one secondary alcohol, and branched-and straight-chain unsaturated carboxylic acids evaluated by EFSA in FGE.05 (2005) and to straight-and branched-chain aliphatic unsaturated primary alcohols, aldehydes, carboxylic acids, and esters evaluated by EFSA in FGE.06 (2004)

Journal of Sustainable Agriculture, 1995

... Katherine Díaz-Knauf is a former Research Associate, and Christine Bruhn is Director, Center ... more ... Katherine Díaz-Knauf is a former Research Associate, and Christine Bruhn is Director, Center for ... in the food preferences and con-sumption patterns among the cultural groups (Romero-Gwynn et al. ... Díaz-Knauf, K., López, M., Ivankovich, C., Aguilar, F., Bruhn, C. and H. Schutz. ...

Foodservice Research International, 1993

?-door survey was conducted in Costa Rica 3 identib consumer attitudes and concerns about the saf... more ?-door survey was conducted in Costa Rica 3 identib consumer attitudes and concerns about the safety of fruits and vegetables available in the marketplace. m e sample (n = 98) was randomly selected from a panel of 255 households in urban and rural areas. More than half the respondents (54%) expressed confidence in the safety of the produce available in the marketplace, while a minority (11 %) reported avoiding the consumption of some produce due to food safety concerns. A majority of respondents (64% agreed that the only way farmers control pests today is by using pesticides and that these are used indiscriminately (57%). Yet, 53% of the sample agreed that growers today use many practices to protect the environment and provide safe food. Consumers (48%) perceived farmers to be concerned about the environment and safe food, and agree (43 %) that farmers carefully manage the use of chemicals and other techniques to produce clean, safe, fresh food. m e majority (65%) of respondents were aware of the training programs and technical assistance provided to farmers on the use of chemicals by the Ministry of Agriculture and Cattle (MAG). Information sources on which consumers rely are television (92 %), radio (73 %), and newspapers (63%). mese findings show that while many consumers are not completely confident in the chemical safety of produce, few have reduced produce consumption. Consumers are also concerned with the perceived indiscriminate use of pesticides by farmers. Since public confidence appears to be high for MAG, the government may want to use MAG and the mass media to provide consumer education programs on food safety that specifically address the use of pesticides by farmers.

Human Mutation, 1993

We have previously developed conditions to screen for TP53 point mutations inside the conserved d... more We have previously developed conditions to screen for TP53 point mutations inside the conserved domains II-V of the gene by using constant denaturant gel electrophoresis (CDGE). The present study reports conditions for screening more of the codons in the frequently mutated region exon 5-8 and for detecting mutations in sequences encoding functional domains in the N- and C-terminal part of the protein. The ability of the CDGE technique to detect mutations was studied using controls with known sequence deviations. The resolution power of the technique to separate different types of mutations was tested by using seven different single base pair mutants all residing in a stretch of four base pairs. All mutants were separated from the wild type. The established CDGE screening strategy was then used to look for mutations in DNA from 28 osteosarcomas. Six (21.5%) of the samples were shown to have a TP53 mutation, and the exact characterization was performed by direct sequencing. All of these were within the frequently reported mutated region exon 5-8.

Fluid Phase Equilibria, 2012

New experimental excess molar enthalpy data (304 points) of the binary systems dibutyl ether (DBE... more New experimental excess molar enthalpy data (304 points) of the binary systems dibutyl ether (DBE) or 1-butanol and 1-hexene, or methylcyclohexane or toluene at 298.15 K and 313.15 K, and DBE or 1-butanol and cyclohexane or 2,2,4-trimethylpentane (TMP) at 313.15 K at atmospheric pressure are reported. A quasi-isothermal flow calorimeter has been used to make the measurements. All the binary systems show endothermic character except the system DBE + 1-hexene at both temperatures. The experimental data for the binary systems have been fitted using the Redlich-Kister rational equation. The values of the standard deviation indicate good agreement between the experimental results and those calculated from the equations.

Fluid Phase Equilibria, 2009

Experimental excess molar enthalpies of the ternary systems dibutyl ether (DBE)+1-butanol+benzene... more Experimental excess molar enthalpies of the ternary systems dibutyl ether (DBE)+1-butanol+benzene and the corresponding binary systems at T=298.15K and T=313.15K at atmospheric pressure are reported. A quasi-isothermal flow calorimeter has been used to make the measurements. All the binary and the ternary systems show endothermic character. The experimental data for the binary and ternary systems have been fitted using the Redlich-Kister equation and the NRTL and UNIQUAC models. The values of the standard deviation indicate good agreement between the experimental results and those calculated from the equations.