Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 5 de 5
Filter
1.
Rev. biol. trop ; 69(3)sept. 2021.
Article in Spanish | LILACS, SaludCR | ID: biblio-1387676

ABSTRACT

Resumen Introducción: Los servicios ecosistémicos (SE) de provisión suministrados por los agroecosistemas de huertos familiares (AEHF) se refieren a los beneficios tangibles que las personas obtienen del ecosistema. Aunque los AEHF, han sido ampliamente estudiados, pocos son los trabajos que evidencian su abordaje desde una perspectiva integral, la cual incorpore características biofísicas y económicas al mismo tiempo. Objetivo: Realizar un análisis integral los servicios ecosistémicos de provisión suministrados por agroecosistemas de huertos familiares del Estado de México. Métodos: Se recopilo información sobre los SE de provisión (identificación, usos, destinos y generación de ingresos) mediante entrevistas semiestructuradas, cuestionarios, inventarios de especies, observaciónes directas, y recorridos en campo entre Marzo a Diciembre de 2019 en tres comunidades rurales, con la participación de 42 familias propietarias de los huertos familiares. Resultados: Se identificaron un total de seis SE de provisión asociados a 212 especies, las cuales fueron distribuidas en 172 géneros y 82 familias. Los Principales usos que los propietarios de los huertos dieron a los SE de provisión fueron ornamentales (51 %), seguidos de los alimenticios (39 %) y medicinales (32 %), donde especies como Cymbopogon citratus, Persea americana, Punica granatum, Zea mays e Inga jinicuil, tuvieron los mayores valores de uso (V. U. = 4). El destino de la producción fue autoconsumo, venta e intercambio; siendo el primero, la principal estrategia de sobrevivencia utilizada por los hogares. La venta de productos comestibles en fresco, así como de sus derivados represento ingresos brutos promedio de 1 333.47 USD/año para los propietarios de los huertos familiares. Conclusiones: Los servicios ecosistémicos de provisión proporcionados por los huertos familiares son vistos como una fuente importante de recursos, los cuales permiten satisfacer necesidades múltiples de los hogares rurales, catalogados en pobreza extrema.


Abstract Introduction: Provisioning ecosystem services (ES) provided by agroecosystems of family orchards (AEFO) refer to the tangible benefits that people obtain from the ecosystem. Although AEFO have been widely studied, few studies show their approach from an integral perspective, which incorporates biophysical and economic characteristics at the same time. Objective: To carry out an integral analysis of provisioning ecosystem services provided by agroecosystems of family orchards from State of Mexico. Methods: Information about provisioning ecosystem services (identification, uses, destination and income generation) were collected between March to December 2019 from three rural communities by involving 42 families with a family orchard using semi-structured interviews, questionnaires, species inventories, direct observation and field trips. Results: A sum of six provisioning ecosystem services were identified, which were associated to 212 species, distributed in 172 genera and 82 families. The main uses that the owners of the orchards gave to provisioning ES were ornamental (51 %), followed by food (39 %) and medicinal (32 %), where species such as Cymbopogon citratus, Persea americana, Punica granatum, Zea mays e Inga jinicuil, had the highest use values (U. V. = 4). The destination of the production was self-consumption, sale and exchange, being the first the main survival strategy used by households. Sale of edible products in fresh, as well as their derivatives, represented an average gross income of 1 333.47 USD/year for the owners of the family orchards. Conclusions: Provisioning ecosystem services provided by family orchards seen as an important source of resources, which allow the households of rural communities classified in extreme poverty to cover multiple needs.


Subject(s)
Ecosystem , Sustainable Agriculture , Mexico
2.
Macromol Rapid Commun ; 40(19): e1900299, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31348584

ABSTRACT

This paper describes the preparation, physical properties, and electric bending actuation of a new class of active materials-ionic liquid crystal elastomers (iLCEs). It is demonstrated that iLCEs can be actuated by low-frequency AC or DC voltages of less than 1 V. The bending strains of the unoptimized first iLCEs are already comparable to the well-developed ionic electroactive polymers. Additionally, iLCEs exhibit several novel and superior features, such as the alignment that increases the performance of actuation, the possibility of preprogrammed actuation patterns at the level of the cross-linking process, and dual (thermal and electric) actuations in hybrid samples. Since liquid crystal elastomers are also sensitive to magnetic fields and can also be light sensitive, iLCEs have far-reaching potentials toward multiresponsive actuations that may have so far unmatched properties in soft robotics, sensing, and biomedical applications.


Subject(s)
Elastomers/chemistry , Liquid Crystals/chemistry , Electric Capacitance , Molecular Structure
4.
J Mol Model ; 16(3): 401-9, 2010 Mar.
Article in English | MEDLINE | ID: mdl-19626351

ABSTRACT

G-protein coupled receptors (GPCR) belong to the largest group of membrane proteins involved in signal transduction. These receptors are implicated in diverse physiological and pathological events. The human beta(2) adrenergic receptor (hbeta(2)AR) is one of the few GPCRs whose 3-D structures are available on the Protein Data Bank. Because there is great interest by drug developers for hbeta(2)AR as a target, it is necessary to study its ligand-recognition process at the atomic level. The hbeta(2)AR can recognize both R/S enantiomeric ligands, R-agonists result in a greater activation than do S-agonists (eutomers and distomers for activation, respectively), according to experimental results. In this work is reported the ligand recognition on a refined hbeta(2)AR-structure of a set of well-known R/S-ligands by means of docking studies. Data obtained in silico were analyzed and compared with those reported in vitro. The theoretical affinity values were reproduced for agonists, but not for antagonist (or inverse agonists). However, theoretical data for R-antagonists are in function to experimental data. The theoretical results confirm the role of amino acids previously reported by mutagenesis studies due to their important roles in drug affinity and stereoselectivity.


Subject(s)
Adrenergic beta-2 Receptor Agonists , Adrenergic beta-2 Receptor Antagonists , Models, Molecular , Albuterol/chemistry , Albuterol/pharmacology , Binding Sites , Crystallography, X-Ray , Humans , Ligands , Receptors, Adrenergic, beta-2/chemistry , Stereoisomerism
5.
Interciencia ; 28(6): 355-361, jun. 2003.
Article in Spanish | LILACS | ID: lil-356806

ABSTRACT

Se discute el fenómeno de la innovación y la necesaria transformación que debe sufrir la aproximación tradicional que en torno al mismo se ha hecho desde las ciencias económicas. Se identificaron las principales características evolutivas de la innovación y se pone de manifiesto la economía neo-clásica no provee herramientas adecuadas ni para estudiar el fenómeno ni para derivar acciones prácticas para conducirlo. A la luz de ello, se sostiene que el necesario abandono de algunas de las más caras pretensiones neoclásicas, en particular la existencia de una única y mejor manera de gerenciar los procesos económicos, tiene una crucial consecuencia para los gobiernos: las políticas de intervención para promover la innovación ahora pueden, y deben, ser soportadas por argumentos mucho más ricos, extensos y comprehensivos que los sugeridos por la economía neoclásica.


Subject(s)
Diffusion of Innovation , Economics , Organizational Innovation/economics , Venezuela
SELECTION OF CITATIONS
SEARCH DETAIL