Perception Of Socio-environmental Conflicts In Mining Areas: The Case Of The Mirador Project In Ecuador

In order to analyse the socio-environmental conflicts it is essential to pay attention to people's perception, because environmental problems can lead to different forms of conflict according to local economic and socio-cultural context. The main objective of this research is to determine the perception of the public about the different socio-environmental conflicts in the area of influence of the Mirador Project, the first project of large-scale mining in Ecuador. To do so, a representative sample of the general population was used to analyse how socio-environmental conflicts were perceived. Furthermore, the arguments and reasons that led people to take extreme positions on mining were also analysed. In both cases, the opinions about perceived conflicts at the time of the investigation and expected threats with the start of mining phase were examined.192234

A new hybrid: Artesunate-Tumacona B

In recent years, the emergence of Plasmodium strains resistant to artemisinin derivatives, such as the commercial antimalarial Artesunate, has been detected. For this reason, in the search for new strategies to malaria control, we used the antiplasmodial activity of natural products from plant Solanum nudum, such as Tumacona B (SN2), to synthesize a new hybrid Artesunate-Tumacona B. The antiplasmodial activity and cytotoxicity of this hybrid was evaluated in vitro. We found a potent activity with IC50 = 0.0044μM in the strain 3D7 (chloroquine sensitive) and IC50= 0.0059 μM for the strain FCR3 (chloroquine resistant) and low cytotoxicity in HepG2 human liver cells with a CC50 = 12.6 μM. This makes the hybrid a new and promising compound

Air-steam gasification of char derived from sewage sludge pyrolysis. Comparison with the gasification of sewage sludge

Air-steam gasification of char derived from fast pyrolysis of sewage sludge has been experimentally evaluated in a fluidized bed as a route towards a full recovery of energy from sewage sludge. The results have been compared with those obtained from the direct gasification of sewage sludge in order to evaluate how the previous pyrolysis stage affects the subsequent gasification process. The fixed carbon content in the solid increased after the pyrolysis stage so that heterogeneous reactions of carbon with steam or CO2 assumed greater importance during char gasification than during sewage sludge gasification. Furthermore, char gasification led to an improvement in the gas yield -calculated on a dry and ash-free basis (daf)- due to the increased concentration of carbon in the organic fraction of the solid after the pyrolysis step, with an increase in the average CO yield of about 70% -in terms of g/kg solid daf-. The reduction in the fraction of carbon which forms tar is another advantage of char gasification over the direct gasification of sewage sludge, with an average decrease of about 45%. Regarding the influence of the operating conditions, the response variables were mainly controlled by the same factors in both processes

Air-steam gasification of sewage sludge in a fluidized bed. Influence of some operating conditions

An experimental work was carried out to investigate the viability of energy recovery from the air–steam gasification of sewage sludge. The relative influence of different factors, as well as the effect of their possible interactions, has been determined by means of analysis of variance. Temperature was found to be the most influential factor for most of the variables analyzed. Solid yield (35–41 wt.%) and tar content (11–45 g/m3 STP) were largely reduced with temperature, whereas gas production (0:89 -- 1:32 m3 STP/kg sewage sludge dry and ash free), carbon yield to gas phase (62–90 wt.%), gasification efficiency (39–66%), and H2 and CO yields (20–52 and 137–414 g/kg sewage sludge dry and ash free, respectively) were improved at high temperature. Other important parameters for the end-use of the gas such as its heating value (4.12–6.20 MJ/m3 STP) and its H2/CO molar ratio (1.46–3.25) were greatly influenced by the composition of the gasification medium, since the increase in the steam to oxygen ratio was favorable for both. The comparison of experimental and theoretical results highlights that equilibrium was not reached during the experimental run

Variation of growth performance of the striped venus clam Chamelea gallina (Mollusca: Bivalvia) (Linnaeus, 1758) in relation to environmental variables along the southern part of its geographic range

This study reports relative growth, shell length-age keys and growth performance indices (overall growth performance (OGP) and phi prime) for the striped venus Chamelea gallina from the Huelva coast in southwest (SW) Spain. The morphometric relationship shell height (SH)/shell length (SL) presented isometric growth whereas SL/shell width (SW) and SL/weight (W) displayed negative allometric growth. Shell length at age was estimated through length-frequency distribution (LF) and internal shell growth bands by acetate peel method (AP). C. gallina population consists mainly of three age classes with shell lengths around 13-15 mm for the first year, 25 mm for the second year and 30 mm for the third year. The OGP and phi prime values obtained in the present study are within the range of values for other C. gallina populations from the Gulf of Cádiz. Nevertheless, marked differences in growth performance were observed between populations from the Black Sea (lower growth performance) and from other locations along the southern distribution area of this species, which may be related to the low levels of temperature (SST), salinity (SSS) and chlorophyll-a (chl-a) concentration that exhibit large intra-annual fluctuations.En prensa0,371

Exploring the SO(32) Heterotic String

We give a complete classification of Z_N orbifold compactification of the heterotic SO(32) string theory and show its potential for realistic model building. The appearance of spinor representations of SO(2n) groups is analyzed in detail. We conclude that the heterotic SO(32) string constitutes an interesting part of the string landscape both in view of model constructions and the question of heterotic-type I duality.Comment: 21 pages, 5 figure

Gasificación de lodos procedentes de Estaciones Depuradoras de Aguas Residuales. Estudio del proceso para la limpieza y mejora de las propiedades del gas producto

La valorización y gestión de los fangos generados en las Estaciones Depuradoras de Aguas Residuales (EDAR) es un asunto de interés en la actualidad debido al aumento del volumen generado de dicho residuo y a las restricciones impuestas sobre las vías de gestión habituales. La gasificación de estos lodos para la obtención de un gas de síntesis y/o con buenas propiedades combustibles es una posible alternativa ya que permitiría la valorización de este residuo. Sin embargo, la formación de alquitranes (hidrocarburos condensables) durante la gasificación supone ciertas limitaciones para la aplicabilidad del gas. Entre las medidas existentes para la reducción del contenido de alquitranes se encuentra una correcta selección de los parámetros de operación en el propio gasificador. Por ello, la primera parte de este trabajo se centra en el estudio de la influencia de variables como la temperatura, el tipo de agente gasificante utilizado (aire o mezclas de aire y vapor de agua) o la cantidad de agente gasificante utilizado por kilogramo de lodo procesado en el lecho fluidizado. Una vez optimizadas las condiciones de operación del gasificador, la segunda parte del trabajo consiste en la aplicación de catalizadores para el reformado de los alquitranes en fase vapor. Con el objetivo de evaluar la actividad de distintos tipos de catalizadores se está trabajando en una planta de lecho fijo, en la que se alimenta un gas con una composición similar al gas de gasificación y se utilizan compuestos modelo para simular la presencia de alquitranes en el gas. Los catalizadores que mejores resultados ofrezcan serán utilizados en la limpieza del gas real que se obtiene en la gasificación de los lodos, incorporando un lecho catalítico aguas abajo del gasificador

High-level quinolone resistance is associated with the overexpression of smeVWX in Stenotrophomonas maltophilia clinical isolates

AbstractStenotrophomonas maltophilia is the only known bacterium in which quinolone-resistant isolates do not present mutations in the genes encoding bacterial topoisomerases. The expression of the intrinsic quinolone resistance elements smeDEF, smeVWX and Smqnr was analysed in 31 clinical S. maltophilia isolates presenting a minimum inhibitory concentration (MIC) range to ciprofloxacin between 0.5 and > 32 μg/mL; 11 (35.5%) overexpressed smeDEF, 2 (6.5%) presenting the highest quinolone MICs overexpressed smeVWX and 1 (3.2%) overexpressed Smqnr. Both strains overexpressing smeVWX presented changes at the Gly266 position of SmeRv, the repressor of smeVWX. Changes at the same position were previously observed in in vitro selected S. maltophilia quinolone-resistant mutants, indicating this amino acid is highly relevant for the activity of SmeRv in repressing smeVWX expression. For the first time SmeVWX overexpression is associated with quinolone resistance of S. maltophilia clinical isolates