77 research outputs found
Base metal budgets of a small catchment in a tropical montane forest in South Ecuador
In a tropical montane rain forest in south Ecuador, the alkali and earth alkali metals Ca, Mg, K, and Na are supplied by weathering of the parent substrate consisting of phyllites and metasandstones and by atmospheric inputs. Phases of acid deposition are interrupted by alkalinization through episodic basic dust deposition. Although the biological productivity of most terrestrial ecosystems is thought to be N- and/or P-limited, there is increasing evidence that the essential plant nutrients K, Na, Mg and Ca can also limit biological functioning.
We quantified biological and geochemical contributions to base metal fluxes and set up a metal budget of a ca. 9.1-ha large catchment from 1998 to 2013. The catchment is characterized by a high annual interception loss (28–50 %) and a low contribution of stem flow to throughfall. Mean total annual soil input (throughfall + stemflow + litterfall) was 13800 ± 1500 mg m-2 (Ca, mean ± SD), 19000 ± 1510 (K), 4690 ± 619 (Mg) and 846 ± 592 (Na) of which 22 ± 6 % (Ca), 45 ± 16 (K), 39 ± 10 (Mg) and 84 ± 33 (Na) were leached to soil horizons below the organic layer. The three nutrient metals Ca, K and Mg were thus to a large part retained in the biotic part of the catchment.
The canopy budget of K was consistently and most pronouncedly negative. The canopy budgets of Ca and Mg were closely correlated and in most years negative, while the budget of Na was consistently positive, indicating net retention of this element in the canopy. The mineral soil retained 79–94 % of Ca, K and Mg, while Na was net released from the mineral soil.
The size of mainly biologically controlled aboveground fluxes of Ca, K and Mg was 1-2 orders of magnitude larger than that of mainly geochemically controlled fluxes which are driven by sorption to soil and weathering. Annual net hydrological fluxes (bulk deposition – stream flow) were –66 ± 278 mg m-2 (Ca), 361 ± 421 (K), –188 ± 159 (Mg) and –1700 ± 587 (Na). If estimated dry deposition was included, the system accumulated 86 kg Ca ha-1 and 199 kg K ha-1, had a nearly balanced budget of Mg (+0.3 kg ha-1) and lost 56 kg of Na ha-1 in the last 15 years. The strongest driver of all budgets was the input flux into the various compartments
Chemical composition and antimicrobial activity of Myrcianthes fragrans essential oil, a natural aromatizer of the traditional Ecuadorian beverage colada morada
Ethnobotanical and ethnomedicinal relevance: The importance given in Ecuador to the rescue of traditional knowledge and nutritional value of ancestral foods and drinks, has stimulated our investigation of the chemical composition and some biological activities of M. fragrans (‘arrayán’) essential oil, a natural aromatic additive used in the preparation of the traditional fruit-juice ‘colada morada’ which is typically drunk in the Day of the Dead or All Soul´s Day. Material and methods: Different essential oils of Myrcianthes fragrans (Sw.) McVaught were obtained by hydrodistillation of the aerial parts of the plant collected in Cerro Villonaco (Loja-Ecuador) at three different phenological growth stages, i.e., during foliation (Fo), flowering (Fl) and fruiting (Fr) stages. The chemical compositions of the essential oils were determined by GC/MS and GC/FID techniques. The antimicrobial activities were determined by the broth microdilution method and reported as minimal inhibitory concentration (MIC, ug/mL). Aims of the study: i) to investigate the traditional uses of arrayán (M. fragrans) in the South region of Ecuador; ii) to identify the main components of the essential oils isolated at different phenological stages; iiì) to test the antimicrobial activity of the essential oils against bacteria and yeasts causing human ailments and a yeast causing food spoilage. Results: 37, 46 and 38 compounds, representing 96.5%, 96.2%, and 95.6% of the three essential oils (Fo, Fl and Fr), respectively, have been identified. Oxygenated monoterpenes (OM) were the major components with percentages of 63.1 (Fo), 49.4 (Fl), and 61.9% (Fr), respectively. The main constituents of the essential oils were the monoterpene aldehydes geranial (1) and neral (2), the content of which varied, depending on the phenological development stage of the plant, spanning from 31.1% and 23.6% (Fo), to 23.6% and 17.8% (Fl), and 29.7% and 24.3% (Fr), respectively. In vitro antimicrobial tests showed that the essential oils from M. fragrans exhibited good activity against the Gram-negative bacteria, K. pneumoniae, and against the yeasts, C. albicans and S. cerevisiae. Conclusions: The oil is characterized by a high concentration of the monoterpene aldehydes geranial and neral (citral), that make the aroma of colada morada prepared in southern Ecuador quite different from the beverage made in other regions of the country, where other types of myrtles (Myrtaceae spp.) are used. Moreover, the oil may become a new rich source of the important industrial chemical citral. The pleasant aromatic properties and the good in vitro antimicrobial activity of arrayán oil suggest a plausible scientific explanation for the traditional uses of the plant not only as a natural aromatizer of a traditional beverage but also as a natural anti-infective and anti-yeast agent
Decision-making tool for enhancing the sustainable management of cultural institutions: season content programming at Palau de la música catalana
There has been an increasing relevance of the cultural sector in the economic and social development of different countries. However, this sector continues without much input from multi-criteria decision-making (MDCM) techniques and sustainability analysis, which are widely used in other sectors. This paper proposes an MCDM model to assess the sustainability of a musical institution’s program. To define the parameters of the proposed model, qualitative interviews with relevant representatives of Catalan cultural institutions and highly recognized professionals in the sector were performed. The content of the 2015–2016 season of the ‘Palau de la Música Catalana’, a relevant Catalan musical institution located in Barcelona, was used as a case study to empirically test the method. The method allows the calculation of a season value index (SVI), which serves to make more sustainable decisions on musical season programs according to the established criteria. The sensitivity analysis carried out for different scenarios shows the robustness of the method. The research suggests that more complex decision settings, such as MCDM methods that are widely used in other sectors, can be easily applied to the sustainable management of any type of cultural institution. To the best of the authors’ knowledge, this method was never applied to a cultural institution and with real data
Adoption of e-commerce by individuals and digital divide: Evidence from Spain
E-commerce penetration rates are distant among those groups of individuals with the lowest and the highest levels of online shopping adoption. This is an indicator of digital divide, having negative effects in terms of untapped opportunities for people, companies and the whole economy. Key socioeconomic and demographic determinants of adoption of ecommerce are explored, analyzing a dataset of 174,776 observations for the period 2008-2017 in Spain. The empirical analysis is based on a standard neoclassical utility maximization framework. Linear probability model, logistic regression, and Heckman’s sample selection correction model have been used. The results suggest that e-commerce adoption is positively related with being male, having higher levels of education, income and digital skills, being Spanish, and being employed; while being female, older and belonging to a household of two or more members have negative effects. An interaction between digital skills and age has been introduced in the model, where high digital skills seem to have a positive influence, partly counteracting the lower odds for some age groups. Policy recommendations related to demand and supply measures are suggested to foster the adoption of e-commerce
Determinación de [CAP] conocimientos, actitudes y prácticas de la población de El Valle zona "A" en relación a la tuberculosis. Azuay 1988
Doctor en Medicina y CirugíaCuenc
Estudio de las causas de la mortalidad del cantón Cuenca durante el año 1981
Licenciado en EnfermeríaCuenc
El hábitat indígena de Saraguro
El medio en el que se desenvuelve el indígena de Saraguro, presenta condiciones particulares que determinan características físicas, psíquicas y sociales, especialmente en lo que respecta a la vivienda. Por ello luego de un análisis se establecen tipologías que de manera general contienen espacios para cocina, dormitorios, bodegas, corredores. De lo cual en el presente estudio se dan recomendaciones adoptables a todas las tipologías como son: Seleccionar materiales adecuados para evitar el fracaso de la estructura, dotar del espacio necesario para cada función, mejorar calidad ambiental abriendo ventanas, mejorar el sistema constructivo del bahareque, y solucionar los pisos de los localesArquitectoCuenc
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