Search results for "agrícola"
showing 10 items of 72 documents
Validación de un cuestionario para medir retrospectivamente la exposición laboral a plaguicidas
1997
ResumenObjetivosValidar un cuestionario diseñado para medir retrospectivamente la exposición laboral a plaguicidas en un estudio de casos y controles sobre trabajadores expuestos a plaguicidas y malformaciones congénitas.MétodosSe compara la información obtenida mediante una entrevista personal con 56 agricultores con: 1) una entrevista con los empleadores de los agricultores, 2) la observación directa de los lugares de trabajo y 3) un cuestionario que cumplimentaron los agncultores durante la realización del Programa de Capacitación para Manipuladores de Plaguicidas.ResultadosLos índices de exactitud y fiabilidad fueron altos para las variables «cultivos trabajados», «períodos de tratamien…
Agricultura i alimentació: realitats presents i desafiaments futurs
2015
Uno de los retos de la humanidad es como alimentar a una población en crecimiento sin dañar al planeta. Pensar en las necesidades actuales sin obviar que las decisiones que tomemos pueden poner en cuestión las generaciones futuras. La clave es el punto de equilibrio entre intensificación y sostenibilidad, dos conceptos que demasiado a menudo, se han visto como contradictorios y que mediante la innovación deben retroalimentarse.
La regulación de la calidad diferenciada en los productos agroalimentarios: el caso del vino
2023
Dentro del amplio abanico de regulaciones referidas al área agroalimentaria, una de las más destacadas es la referida a los regímenes de calidad. Desde hace siglos nos encontramos con productos provenientes de zonas específicas cuya reputación hacía que fueran buscados por consumidores de otras regiones, a veces muy lejanas. Cuando la demanda era muy elevada y parte de ella procedía de grupos de población con alta capacidad adquisitiva ello implicaba la escasez del producto y la inevitable tentación hacia el fraude. Por eso no es de extrañar que en muchas de esas zonas surgieran las primeras regulaciones al respecto de la calidad de los productos agroalimentarios, siendo frecuentes las refe…
Identification of Bioactive Compounds in Polar and Nonpolar Extracts of Araujia sericifera
2017
Abstract Araujia sericifera is a native perennial, climbing laticiferous shrub from South America that is currently naturalized in many other countries. Previous data describe promising properties for A. sericifera, but no systematic study of its bioactive compounds and possible medicinal applications has been conducted to date. In the present study, aerial parts of A. sericifera (leaves, stems, and fruits) were explored by combining GC-MS and NMR spectroscopy analysis for both nonpolar (hexane) and polar (methanol) extracts. The hexanic extracts contained high amounts of pentacyclic triterpenes including two new metabolites, 3-tigloyl germanicol (18) and 3-tigloyl lupeol (19). The methanol…
Indigenismo y migracionismo. Aspectos de la neolitización en la fachada oriental de la Península Ibérica
1996
This paper discusses various aspects on the origins of the Neolithic in the Iberian Peninsula. The dual model is proposed as an alternative to the dichotomy of demie (migrationist) and non-demic (indigenist) explanations. The application of this model in eastern Spain offers an opportunity to evaluate its potential to account for diversity in processes associated with the origins of food production and their spatial organisation.
Common receptor for Bacillus thuringiensis toxins Cry1Ac, Cry1Fa, and Cry1Ja in Helicoverpa armigera, Helicoverpa zea and Spodoptera exigua
2005
ABSTRACT Binding studies using 125 I-Cry1Ac and biotinylated Cry1Fa toxins indicate the occurrence of a common receptor for Cry1Ac, Cry1Fa, and Cry1Ja in Helicoverpa armigera , Helicoverpa zea , and Spodoptera exigua . Our results, along with previous binding data and the observed cases of cross-resistance, suggest that this pattern seems to be widespread among lepidopteran species.
Extraction of lipids from microalgae using classical and innovative approaches
2022
Microalgae, as a photosynthetic autotrophic organism, contain a variety of bioactive compounds, including lipids, proteins, polysaccharides, which have been applied in food, medicine, and fuel industries, among others. Microalgae are considered a good source of marine lipids due to their high content in unsaturated fatty acid (UFA) and can be used as a supplement/replacement for fish-based oil. The high concentration of docosahexaenoic (DHA) and eicosapentaenoic acids (EPA) in microalgae lipids, results in important physiological functions, such as antibacterial, anti-inflammatory, and immune regulation, being also a prerequisite for its development and application. In this paper, a variety…
Specific binding of Bacillus thuringiensis Cry2A insecticidal proteins to a common site in the midgut of Helicoverpa species
2008
ABSTRACT For a long time, it has been assumed that the mode of action of Cry2A toxins was unique and different from that of other three-domain Cry toxins due to their apparent nonspecific and unsaturable binding to an unlimited number of receptors. However, based on the homology of the tertiary structure among three-domain Cry toxins, similar modes of action for all of them are expected. To confirm this hypothesis, binding assays were carried out with 125 I-labeled Cry2Ab. Saturation assays showed that Cry2Ab binds in a specific and saturable manner to brush border membrane vesicles (BBMVs) of Helicoverpa armigera . Homologous-competition assays with 125 I-Cry2Ab demonstrated that this toxi…
Lack of Cry1Fa binding to the midgut brush border membrane in a resistant colony of Plutella xylostella moths with a mutaton in the ABCC2 locus
2012
ABSTRACT Previous studies reported “mode 1” Bacillus thuringiensis resistance in a colony of diamondback moths (NO-QA), and recently, this resistance has been mapped to an ABC transporter ( ABCC2 ) locus. We report the lack of binding of Cry1Fa to insects derived from this colony and compare our data with those from other insects with ABCC2 -associated resistance.
Interaction of Bacillus thuringiensis Cry1 and Vip3A Proteins with Spodoptera frugiperda Midgut Binding Sites
2009
ABSTRACT Vip3Aa, Vip3Af, Cry1Ab, and Cry1Fa were tested for their toxicities and binding interactions. Vip3A proteins were more toxic than Cry1 proteins. Binding assays showed independent specific binding sites for Cry1 and Vip3A proteins. Cry1Ab and Cry1Fa competed for the same binding sites, whereas Vip3Aa competed for those of Vip3Af.